Beyond reasonable doubt: reconsidering Neanderthal aesthetic capacity

Abstract

An aesthetic sense—a taste for the creation and/or appreciation of that which strikes one as, e.g., attractive or awesome—is often assumed to be a distinctively H. sapiens phenomenon. However, recent paleoanthropological research is revealing its archaeologically visible, deeper roots. The sensorimotor/perceptual and cognitive capacities underpinning aesthetic activities are a major focus of evolutionary aesthetics. Here we take a diachronic, evolutionary perspective and assess ongoing scepticism regarding whether, and to what extent, aesthetic capacity extends to our evolutionary cousins, the Neanderthals. The goal of this article is twofold. First, it serves as a defence of the attribution of Neanderthal aesthetic capacity by marshalling archaeological data best explained by positing a Neanderthal aesthetic sense. Second, it offers an opportunity to make progress on understanding some epistemically relevant features of the wider debate in evolutionary aesthetics. First, we outline and analyse a range of distinct ‘sceptical arguments’ derived from attitudes and claims found in the literature and broader debate that aim to dial down the case for Neanderthal aesthetic capacity. We show that these arguments not only miss their target, they divert the debate away from more compelling questions. We then consider the case for protoaesthetic capacities and sensitivities in the Acheulean stone tool industry and argue that Neanderthals likely inherited the protoaesthetic package from ancient ancestors that they shared with H. sapiens. Finally, we sketch and defend a research agenda for framing Neanderthal aesthetic niche(s) beyond H. sapiens-derived standards, which we see as a priority for future archaeological, cognitive, and philosophical research. While we resist sceptical arguments and the often-implied inferiority of Neanderthals to humans, we also deny that Neanderthals and ancient humans were indistinguishable. Understanding the differences is an important goal of interpretation, and we apply this line of reasoning to the case of aesthetics.

Across diverse cultures, aesthetic experience stands as a central and highly-valued facet of human lifeways. Aesthetic experience—“an emotionally heightened focus on an item’s attractiveness or awesomeness” (Davies, 2012, p.1); “attending in a discriminating manner to forms, qualities or meaningful features of things, attending to these for their own sake or for the sake of this very experience” (Stecker, 2006, p. 4)—manifests itself in the production or selection of items (objects, events, etc.) with aesthetic qualities (qualities which render the item appealing or unappealing; attractive, awesome, garish, bland, ugly, etc.). As such, aesthetic activities and items are archaeologically visible. Ancient cave paintings, musical instruments, personal adornments, decorative grave goods, and other traces establish ancient humans as possessing aesthetic capacity: an aesthetic sense or taste and aesthetically-related abilities or skills. Just think of the many ancient paintings covering the cave walls and ceilings at Lascaux. But is aesthetic capacity peculiar to Homo sapiens alone? In this article, we argue that current evidence is at odds with the aesthetic domains’ long-held treatment as a unique H. sapiens phenomenon.¹ While new attributions of an aesthetic sense to our evolutionary cousins, the Neanderthals, continue to spark significant controversy, we claim that much of that scepticism is misdirected. These controversies vary in nature, spanning from technical discussions on the dating and manufactured nature of specific items (Slimak, 2023; White et al., 2020) to the consistency and patterning of traces (Tattersall, 2022; Mellars, 2005) to Neanderthal biological and cognitive endowment (Klein, 1998, 2000). Further, they are often entangled with multiple explanatory goals and burdened with loaded or underspecified terminology (‘art’, ‘symbolism’, etc.). Here we don’t wish to conflate different stances or dismiss the validity of single reasonable doubts. Instead, we urge not to lose sight of the broader picture, as current attention to the case of materially-mediated Neanderthal aesthetics may arguably have such a diverting effect.

In Sect. 1, we briefly lay out what today’s archaeological record tells us about the aesthetic expressions of Neanderthals. In Sect. 2, we consider current views and controversies concerning the lifeways and abilities of the Neanderthals, recapping why a still influential perspective appears to downplay (or even outright deny, when put in its strongest form) their aesthetic capacity. After all, unlike the ancient H. sapiens of the Upper Palaeolithic, Neanderthals appear not to have produced, say, representational cave paintings and musical instruments.² However, the scientific image of Neanderthal behaviour is changing from what it once was, and we leverage both new data and reappraisals to motivate the plausibility of inferring an aesthetic sense from archaeologically known Neanderthal artefacts. In Sect. 3, we offer an evolutionary scenario for the emergence of Neanderthal aesthetic capacity, arguing that Neanderthals very likely would have inherited the range of ‘protoaesthetic’ abilities and sensitivities that our own (H. sapiens) evolutionary lineage inherited from the shared ancestors of both lineages. This includes H. erectus s.l., the earlier producers of the Acheulean stone tool industry.³ We discuss this via a recent argument by Wynn and Berlant (2019). We employ a modest reading of their argument, not requiring several of the theoretical commitments and more speculative suggestions that Wynn and Berlant advocate. Then, in Sect. 4 we explain why it is interesting and important to consider seriously the upshots of a ‘Neanderthal aesthetic’ on its own terms, and suggest ways to address the challenges that come with this project. Finally, Sect. 5 wraps up.

1 Who were the Neanderthals? An evolutionary aesthetics perspective

Archaeological and paleoanthropological research over the past two decades has significantly revised the scientific portrayal of Neanderthals. Neanderthals are today increasingly associated with a set of fascinating phenomena that were once thought to be exclusive to our lineage, H. sapiens (for detailed overviews, see, e.g., Papagianni & Morse, 2022; Nowell, 2023; Finlayson, 2019; Wragg Sykes, 2020). New archaeological discoveries and the reassessment of old repertoires are both driving this ongoing interpretive upheaval, in tandem with increasing paleogenetic and demographic information about the complex patterning of interactions between the Neanderthals and H. sapiens. Evidence of Neanderthal behavioural complexity now includes mortuary treatment of the body (Stiner, 2017), complex underground constructions (Jaubert et al., 2016), fibre technology and rope-making (Hardy et al., 2020), the use of painkillers and possibly penicillin (Weyrich et al., 2017)—and possibly numerical cognition (d’Errico et al., 2018).⁴ However, scepticism still lingers when it comes to their capacity for ‘aesthetics’.

Before providing an overview of the evidence for Neanderthal aesthetics, let’s briefly clarify our approach. This paper will employ a notion of ‘aesthetics’ as invoked by the multidisciplinary fields of evolutionary and anthropological aesthetics, which explore the origins and evolution of aesthetic behaviours and the capacities supporting them. We acknowledge that, historically, aesthetic theory and related philosophical discourse developed in a post-Enlightenment Western milieu, and that narrower and cognitively rich conceptions of aesthetic experience are sometimes discussed by philosophers of art, art historians, and art theorists. However, we do not think that this precludes the application of a ‘broader notion’ outside the narrow context of modern Western fine art (Stecker, 2006; Davies, 2012).⁵ In fact, there are good theoretical reasons for why this should be the case. In some respects, our approach here aligns with the kind of pragmatism and naturalism espoused by the philosopher John Dewey (1934) and others, rejecting both idealizations of the aesthetic and the requirement of any particular cultural or institutional setting for an object or experience to count as ‘aesthetic’. Aesthetics is far more ancient than the contemporary, narrow concept often at stake in philosophy (Dewey, 1934; Leddy & Puolakka, 2023). Discussions of the aesthetic within the context of evolutionary cognitive archaeology over the past few decades support this fundamental intuition, targeting abilities as inferable from, or co-constructed by, varied hominin materiality via the lens of multiple cognitive theories and scientific methodologies (from comparative cognitive analyses, to experimental archaeology and paleoneurology; see Sect. 3). In this paper, we will refer to aesthetic capacities (abilities) of producers of objects, aesthetic experience of both producers and perceivers of objects, aesthetic properties of objects, and so on—and like Dewey, we resist providing a sharp definition of ‘aesthetic’ and its cognates. Indeed, within the evolutionary context and the project of constructing a theoretical space for comparative aesthetics, this paper will argue for the importance of moving away from overly loaded standards for tracking aesthetics in the material record.⁶

In light of this framing, the next section interrogates arguments, reconstructed from claims and attitudes in the literature (and other forums more broadly) that reflect a reluctance to attribute much in the way of aesthetic capacity to Neanderthals. Before getting there, we provide a brief overview of trace evidence that has been attributed to Neanderthals that we take to be aesthetics-related.

The current Neanderthal archaeological repertoire encompasses various types of material traces linked to distinct practices that are indicative of an aesthetic sense. Broadly, these include personal ornaments, pigment use and mixing, engravings on surfaces and objects, and the construction of complex underground structures. We will briefly consider these in turn, recalling this (and other) evidence as we develop our argument throughout the paper.

The case for Neanderthal personal ornamentation has been arguably prompted by excavations and analyses at the French cave Grotte du Renne, yielding pierced animal teeth, bone, ivory, and a fossil shell in association with Neanderthal remains (d’Errico et al., 1998; Welker et al., 2016; see Fig. 1). This association has resisted doubts about the stratigraphic integrity of the site and the dates (Caron et al., 2011; Hublin et al., 2012; see also Sect. 2.3 below). Far from depending on the Grotte du Renne findings alone, the inference that Neanderthals used personal ornamentation rests on several other sites and material types, coupled with indications of their collection, modification and bodily wearing (see also Botha, 2020, ch. 3; see Slimak, 2023 for scepticism against the artisanal modification of those objects⁷). Examples include the perforated marine shells from Cueva de los Aviones in Spain (Zilhão et al., 2010), the pigmented fossil marine shell from Fumane cave (Peresani et al., 2013), the raptor wing bones from Fumane Cave (Peresani et al., 2011), the raptor talons from Krapina in Croatia (Radovčić et al., 2015; see Fig. 2) and potentially also those from Rio Secco Cave and Mandrin Cave (although unambiguous modification is yet to be demonstrated: see, e.g., Romandini et al., 2014) and Cova Foradada (Rodriguez-Hidalgo et al. 2019).

Fig. 1

Neanderthal-associated personal ornaments made of perforated and grooved teeth (1–6, 11), bones (7–8, 10) and a fossil (9); red (12–14) and black (15–16) colourants bearing facets produced by grinding; bone awls (17–23). Reproducible under the terms of the Creative Commons Attribution License. Caron et al. (2011)

Fig. 2

Eagle talons from a Neanderthal site in present-day Croatia. Notches, polished facets and smoothed cut marks suggest they were used as jewellery. Image reproduced with the permission of Springer Nature. From Callaway (2015)

The Neanderthal use of and experimentation with natural pigment is associated with over 70 Mousterian sites and cannot be recounted in full here (for further discussion, see Sect. 4.2). The evidence comprises not only significant amounts of mineral pigments, such as the abundant manganese dioxide from Pech-de-l’Azé (d’Errico & Soressi, 2002), but also their application on objects, such as marine and fossil shells (Zilhão et al., 2010; Peresani et al., 2013), eagle talons (Radovčić et al., 2015) and, not without controversy, surfaces, like large speleothems (Pitarch-Martí et al. 2021) and cave walls (Hoffmann et al., 2018a; but for criticism of the Uranium-Thorium dating and analyses used to licence the Neanderthal attribution, see Pearce & Bonneau, 2018; Slimak et al., 2018; Aubert et al., 2018; Pons-Branchu et al., 2020; White et al., 2020; and for responses to these criticisms, see Hoffmann et al., 2018b, 2019a; Hoffmann et al., 2019b; Hoffmann et al., 2020; see also Sect. 2.1 below).

Engravings and markings are much rarer items at Neanderthal sites, and attesting whether they are signals of an aesthetic sense comes with taming ambiguity in interpretation. These are found on cave floors and walls, such as the famous ‘hashtag’ from Gibraltar’s Gorham Cave (Rodríguez-Vidal et al., 2014; Davidson et al. 2014) or the finger-flutings at La Roche-Cotard (Marquet et al., 2023) and on portable objects like bone (Leder et al., 2021; d’Errico et al., 2018—with the bone object discussed by d’Errico et al. being also tied to discussions on symbolic meaning). Some of these items exhibit less ambiguous, aesthetically-relevant properties and are suggestive of aesthetic capacity with respect to both the modification process and the presumed intentions of their makers (see Sect. 4.1), although we do not here mean to imply that particular intentions are necessary for aesthetic activity.

Finally, we consider the impressive rings of stacked stalagmites at Bruniquel cave (ca. 176 kya) (Jaubert et al., 2016). While the significance and possible social and ritual uses of these rings are open to discussion, the underlying operational chain suggests intentional choices in ‘architectural’ design and in the arrangement of the broken stalagmites, according to a predetermined plan aiming at achieving a specific geometric configuration. Whatever their social or ritual function, we believe these rings can be accounted for as traces of inter alia an aesthetic sense.⁸

Although technical doubts can be raised about the evidential nature of single findings or categories, the overall record now seems to put pressure on the notion of aesthetic capacity as virtually absent or incidental in Neanderthals. That is, we believe there is sufficient data to licence a ‘causal-association inference’ (Currie & Killin, 2019; Killin & Pain, 2023; Currie et al., 2024) to Neanderthal aesthetic capacity. In other words, we believe that despite the potential independent defeasibility of particular findings as evincing a Neanderthal aesthetic sense, the amounting data overall is best explained by positing a Neanderthal aesthetic sense. Scepticism of this move, however, is still present in multiple forms. We’ll turn to these now. Following that, in Sect. 3, we will turn to the evolutionary hypothesis that Neanderthals and modern humans inherited a common protoaesthetic capacity from their common ancestors. Both then developed aesthetic activities further, such that differences (though, we argue, not in terms of Neanderthal–H. sapiens inferiority vs. indistinguishability) are to be expected.

2 Four sceptical arguments

We recognize four sceptical arguments concerning the possibility or extent and relevance of Neanderthal aesthetics. We call these (i) the argument from authorship uncertainty, (ii) the argument from acculturation, (iii) the argument from sporadicity, and (iv) the argument from ‘hardware’. While these arguments aren’t mutually exclusive, we’ve categorized them based on the primary source of scepticism emphasized in each, for simplicity’s sake. Arguably, the polemical targeting of each argument can range from stronger to more subtle forms of scepticism—from claims about aesthetic capacity to claims about the systematicity and interest in aesthetic practices. According to the first argument, Neanderthals have not produced particular traces with aesthetic qualities, at least given the lack of conclusive evidence for Neanderthal authorship (production) of specific materials suggestive of an aesthetic sense. According to a strong version of the fourth argument, which was arguably prominent in the earlier stages of the debate, the Neanderthals could not have produced artefacts with aesthetic qualities due to biological-cognitive constraints. According to the second and third, they could well have (and perhaps did), but with important caveats pertaining to the originality and frequency/abundance of aesthetic expressions, consistent with positing only a partial or limiting aesthetic capacity (which we later call ‘protoaesthetic’, when discussing the Acheulean stone tool record, produced by the common ancestors of both humans and Neanderthals). Overall—as the sceptic party would have it—we’d still be wiser to bet against a genuine Neanderthal aesthetic sense. We believe that is a losing bet. To begin to show why, we discuss the arguments in turn.

2.1 The argument from authorship uncertainty

An important and topical line of sceptical reasoning hinges on ongoing controversies that challenge the attribution of aesthetic practices to Neanderthals (rather than to H. sapiens). That is, this argument mobilizes the difficulties inherent in species attribution of the producers of various artefacts/traces. Recent debates on the possibility of ‘Neanderthal cave art’ are a telling example. The report of red pigment used in painting at three Spanish caves, with dates possibly as ancient as 65 kya, initially suggested Neanderthal authorship of a scalariform shape (La Pasiega), a hand stencil (Maltravieso), and the application of pigment on stalagmites (Ardales) (Hoffmann et al. 2018c). As the first documented presence of our species on the European continent is several thousands of years later, Neanderthals are presumed to be the only hominin species in Iberia. But cave art is difficult to date and much debate is currently targeting the use of the Uranium-Thorium method on the carbonate crusts atop the paintings (as the pigment was not dated directly). The leaching of uranium in cave systems may result in an overestimation of sample ages (see Aubert et al., 2018; White et al., 2020). If so, the paintings could have been produced by some of the earlier modern humans to arrive in the area.

Building upon this momentum, the argument from authorship goes as follows. There are no paradigmatically ‘aesthetic’ products uncontroversially associated with Neanderthals, either due to dating uncertainties or lack of direct association with Neanderthal industries or fossil remains. Further, as the increasing complexity of Homo sapiens’ arrival in and spread throughout Europe is being uncovered—and the estimated arrival of our species on the continent potentially revised (now to 54,000 years ago; Slimak et al., 2022)—the temporal gap of safe and ‘easy’ (i.e., by default) Neanderthal attribution of material traces appears to narrow somewhat: because authorship is uncertain, it is likely any material traces of an apparent aesthetic sense can be chalked up to H. sapiens being present after all, or the impression of dating techniques. Therefore, there remains no conclusive evidence for Neanderthal aesthetic ‘complexity’, let alone what some would consider to be ‘art’.⁹ And so, without conclusive evidence for Neanderthal aesthetic complexity, we’d be better not to suppose a Neanderthal aesthetic sense.

One immediate problem with this kind of argument is that authorship and dating problems do not apply to the full range of the Neanderthal visual cultural repertoire, as we briefly recounted in Sect. 1. When it comes to the use of pigment, for instance, even if its use on cave walls for aesthetic purposes will never be unanimously confirmed, in many other contexts we have clear evidence for the collection and creative mixing of mineral pigments and their use to mark objects (see Wragg Sykes, 2020 for a broader discussion). We return to this in Sect. 4. The lack of confirmation for one specific type of visual cultural expression and related reservations cannot extend to the broad repertoire of visual aesthetic practices safely attributed to Neanderthals (Hawks, 2023). Besides pigment use and personal ornamentation, these include, as we mentioned, engravings—among these, the recently discovered chess-piece-sized deer bone with engraved chevrons from the German ‘Unicorn Cave’ (Leder et al., 2021) and the ‘finger flutings’ traced on the walls of la Roche-Cotard cave in central France (Marquet et al., 2023)—the construction of stalagmite architectures in the bowels of Bruniquel cave (Jaubert et al., 2016), even a picky collection of smooth, green serpentinite pebbles (Peresani et al., 2021). Further, problematic uses of the notion of ‘aesthetics’, which in some contexts is laden with Western modernity’s specific emphasis and connotations, represent another critical interpretive bias inherent in these debates. We wager that underlying many of these sceptical arguments is the presupposition that what counts as ‘aesthetic’ must meet a high bar, attuned to the narrower, modern Western notion of aesthetics found in, say, contexts of fine art appreciation. But on a broad notion of aesthetics, artefacts need not be technically sophisticated, richly symbolic, or otherwise representational, for example, to be windows into the aesthetic capacity of their producers.

2.2 The argument from acculturation

According to the argument from acculturation, the aesthetic products of Neanderthals are largely (if not completely) due to the influence of H. sapiens, who allegedly ‘acculturated’ Neanderthals. In other words, the Neanderthals did not demonstrate much in the way of aesthetic capacity until they acquired it from humans.

H. sapiens and Neanderthals interbred (Villanea & Schraiber, 2019). Multiple episodes of gene flow are now well-documented (Meneganzin & Bernardi, 2023). Given this, intercultural influences are likely. In what we take to be a classic version of this argument (from the pre-genomic era), Paul Mellars noted that the most sophisticated expressions of Neanderthal material culture (such as personal ornamentation) cluster exactly around the time of the arrival of Homo sapiens in Europe (Mellars, 2005). The idea: it is an ‘impossible coincidence’, then, that the timing of our species’ dispersal corresponds to (what was taken to be) a major cultural and technological revolution in the Middle to Upper Palaeolithic transition in Europe. And it would have been a statistically extraordinary event for a species that showed a pattern of technological stagnation for hundreds of thousands of years to suddenly develop, in an independent fashion, the technological and cultural traits typical of anatomically modern humans.

What is denied by this argument is not Neanderthal production but independent inventiveness. Rather, whether by imitation or some other means, the Neanderthal-associated aesthetic artefacts are put down to modern human influence (see, e.g., Hublin et al., 1996). Passionate scientific debates on transitional industries like the Châtelperronian (40–45 kya) of France and northern Iberia—showing both characteristics of Upper Palaeolithic assemblages as well as of Mousterian ones—played a major role. Indeed, there have been several back-and-forths on the identity of its makers and the nature of its emergence (see, e.g., d’Errico et al., 1998 and commentaries and reply within). Today’s evidence supports Neanderthal attribution, although recent anatomically modern human skeletal evidence at Châtelperronian levels gave renewed impetus to the acculturation or cultural diffusion with modification hypothesis (Gicqueau et al., 2023).

One counterargument to scepticism based on the possibility of acculturation is analogous to the one proposed for the authorship argument. Even if acculturation remains a confounding factor in inferring ‘originality’ from particular archaeological signals, at particular sites and in the specific timeframe of possible coexistence with H. sapiens, this problem does not extend to the whole temporal depth of Mousterian history and the evidence of visual culture at much older sites. Examples include the previously mentioned stalagmite constructions at Bruniquel cave, dated to 176 kya (much earlier than any documented Homo sapiens presence on the continent) (Jaubert et al., 2016), the eagle talons from Krapina (Croatia), dated to 120 kya, probably painted and worn as a necklace (Radovčić et al., 2015) or used as a rattle (Wragg Sykes, 2020), or findings of red pigment use at Maastricht-Belvedere at 200–250 kya (Roebroeks et al., 2012). Therefore, the record no longer supports the idea of a long absence of aesthetic inventiveness or aesthetic experience, abruptly kickstarted around the time of arrival of H. sapiens. Furthermore, it should be noted that if the possibility of acquired knowledge poses a problem in terms of originality, it does not necessarily mitigate Neanderthal aesthetic capacity (Bello, 2021). Integrating foreign aesthetic practices into own’s culture does not speak to a lack of capacity nor lack of sensitivity to aesthetic features (although the causes of imitation can be varied). Finally, when comparing archaeological repertoires and detecting a signal demanding explanation, it is worth reiterating the slogan that absence of (more and older) evidence is not evidence of absence. For all we know, Neanderthals (and H. sapiens!) may have engaged in aesthetic behaviours much earlier than currently retrieved archaeological evidence suggests—and some of these, like the modification or arrangement of soft materials, singing, and dance, would have had nearly no chance to leave preservable traces.

2.3 The argument from sporadicity

Let us now consider the argument that although Neanderthals may well have engaged in various forms of aesthetically-related behaviours (engravings, pigment use and experimentation, personal ornamentation, smooth, green serpentinite pebble collection, and so on), the evidence for these things is scarce, in comparison to the abundant evidence available for H. sapiens, showing larger numbers and diversity among Upper Palaeolithic sites (for an overview, see Bello, 2021). This argument often comes in forms that mesh with discussions on symbolic activity when referring to aesthetic items. This is arguably due to symbolic behaviour being a much more critical stake, with some scholars interpreting aesthetic items like personal ornamentation as direct evidence for symbolism (Henshilwood et al. 2004; Zilhão, 2007, 2012; Botha, 2016, ch. 3). Here we hold that the inference to symbolic behaviour goes a step further than what strictly concerns aesthetic capacity, so it won’t concern us here (see also Botha, 2020). Suffice it to say that scholars like Tattersall do indeed attribute to Neanderthals an aesthetic sense (see Tattersall, 2022, ch. 7; although elsewhere defined as ‘rudimentary’, e.g., Tattersall, 2017). However, this is accompanied by remarks on the sporadicity of aesthetic expressions like personal ornaments: “It seems to be quite well established that, once in a long while, they [Neanderthals] did make decorative items” (Tattersall, 2022, ch. 7, our emphasis; see also Tattersall, 2014). When referring to the deer bone at Unicorn Cave and the red pigment from the three Spanish sites, Tattersall interprets them as “hints that are individually suggestive about Neanderthal cognitive complexity, but that are basically floating points, bereft of a larger context in which to place them” (Tattersall, 2022, ch. 7). While this is not leveraged by Tattersall to suggest scepticism about Neanderthal aesthetics per se, it is for a difference in cognitive systematicity and kind (see also Tattersall, 2019) that would be consistent with sceptical attitudes towards Neanderthal aesthetic sense, in its partial or limited reading.

Other treatments of sporadicity emphasize the numerical disparity of personal decoration in Neanderthal and Aurignacian hunter-gatherers to suggest subtle yet fundamental differences in biological and cognitive constraints (Wynn et al., 2016). Importantly, Wynn and colleagues target symbolism, without mentioning Neanderthal aesthetic capacity per se, though that move could presumably be attempted by sceptics so inclined.¹⁰ Remarks of sporadicity are certainly not exclusively voiced by scholars immediately concerned with an overreading of Neanderthal capacities from the available evidence (that is, claims about the rarity of specific items in Neanderthal records are by themselves neutral). When they are, however, they are often coupled with reflections about biological and cognitive underpinnings of differences in aesthetic expression between H. sapiens and Neanderthals (thus taking forms of the argument from ‘hardware’ that we describe in the following section). While we do not think this is the sole possible diagnosis, we think the evidential pattern is interesting and worthy of investigation. But should the sporadic nature of aesthetically-relevant traces in the record undermine inferences to Neanderthal aesthetic capacity? We postpone answering this in more detail here, getting back to the issue of evidential disparity later (Sect. 4.2). But in short, no. A difference in relative frequency of aesthetically-relevant traces between humans and Neanderthals in the archaeological record does not speak against Neanderthal aesthetic capacity—or its lesser or more rudimentary status—especially since, as we pointed out in response to the argument from acculturation above, it is reasonable to assume that many aesthetic activities (of ancient humans as well as Neanderthals) were ephemeral and involved perishable materials, if any. It can speak, however, to a difference.

2.4 The argument from ‘hardware’

Last up is the argument from ‘hardware’. We differentiate between a strong version and weaker variants. Under the strong version, an aesthetic sense and other markers of behavioural modernity—the suite of features ultimately taken to characterize what is distinctive about extant human social and cultural life—would be strongly constrained by biological evolution. This interpretation was certainly dominant a few decades ago, leaning towards an inference to the absence of capacity, based on the absence of striking aesthetic items (for past conceptualizations of Neanderthals, see discussions in Madison, 2016 and Breyl, 2021). Nonetheless, Colagè and d’Errico (2020) argue that an influential set of views would be still committed to what they term a strong ‘chain of dependence’ from genes to brains, to cognitive skills, to behavioural and cultural traits. This implies an exclusively ‘bottom-up’ model of causality: for a change at the behavioural or cultural level to emerge, changes in the genetic endowment or brain functional anatomy or connectivity are necessarily required. Kim Sterelny dubs this view the ‘genetic forcing’ model, according to which material culture would be a simple reflection of genetically canalized cognitive capacities (Sterelny, 2014, 2016). Thus, on the strong version of this line of reasoning, Neanderthals’ different biology (when compared to H. sapiens’) poses major constraints first and foremost for what they could achieve, aesthetic expressions included. As Richard Klein rhetorically asked in the context of the Châtelperronian repertoire, if Neanderthals “were not biologically impeded from behaving in an Upper Paleolithic way”, why didn’t they do so more widely? (2000, p. 32, see also Klein, 1998). The implication being that they could not, biologically speaking.

While we do not deny the reality that genetic and neuroanatomical features can and do constrain material culture and behaviour, we urge against the strong reading of the argument from hardware. There are both theoretical and empirical reasons for this. Theoretically, many capacities are not strongly genetically canalized, as evidenced by the striking absence of a clean mapping in human evolution between morphological changes and changes in the material record (Sterelny, 2021a). Further, the shift towards coevolutionary models to gain access to the evolutionary niche in which past minds operated (e.g.Straffon, 2016, 2019; Sterelny, 2012, 2017, 2021b; Colagè & d’Errico, 2020) holds a lot of explanatory potential. The causal arrow from genes to brain to cognition to behaviour or culture is not unidirectional: dynamic feedback is known to occur, with cultural practices affecting cognition, anatomy, and genetic traits in various ways (Richerson et al., 2010; Beja-Pereira et al., 2003; Wrangham, 2009). The notion of major biological impediments does not capture this dynamic. Empirically, it is worth noting the attributions of protoaesthetic behaviours/sensibilities in hominins much deeper in time than the split between H. sapiens and Neanderthals (Wynn & Berlant, 2019).¹¹ From an evolutionary perspective, this is emerging as a multi-species story. Section 3 will discuss the stone tool record, making the case for Acheulean-associated hominins—Homo erectus s.l. and other derived hominins such as H. heidelbergensis—as (proto-)aesthetic agents (at least in some rudimentary, partial sense, consistent with an incremental evolutionary perspective). This will make artefacts such as the geometrically engraved fossil Pseudodon shell at Trinil (Java) attributed to Asian H. erectus, and approximately half a million years old (Joordens et al. 2014), less of an archaeological oddity.

However, softer versions of this argument move away from interpreting the relationship between genes, brains, and archaeological traces in terms of unidirectional causality and simple correspondence (between biological changes and changes in the archaeological record). This would underline the importance of not dismissing differences in neuroanatomy and brain development in interpreting an archaeological signature. Even if the biological wherewithal can tell only a fraction of the story, it would be a mistake not to attribute causal weight to it in an evolutionary explanation of an observed pattern. Biological differences in two lineages that have followed distinct evolutionary trajectories for hundreds of thousands of years are indeed to be expected (Meneganzin & Bernardi, 2023). Several studies have attested differences between the structure and ontogenetic trajectories of Neanderthal and Homo sapiens brains (Bruner, 2014, 2021) and neurogenesis (Pinson et al., 2022). While Neanderthal brain sizes were comparable if not larger than that of Homo sapiens, they differed in shape, first and foremost by lacking the typical globular conformation of modern humans, with parietal and cerebellar bulging (see Bruner 2021 for a more detailed discussion). We take it that the difficulty here lies in establishing whether—and to what extent—those differences translated into archaeologically visible aesthetically-relevant traces. While this is at the centre of much debate today, we think that the archaeological record, in tandem with independently plausible cognitive models for licencing inference, ultimately provides the strongest empirical constraints on which capacities were in place and how they were expressed. While differences in the ‘hardware’ did exist and did matter, the available and increasing corpus of attributions of Neanderthal aesthetic capacity suggests that these differences in biology are not a death knell for Neanderthal aesthetic capacity per se. As such, given the complexity of our topic—Neanderthal aesthetic experience, production, and selection—as a phenomenon to be probed and explained, the challenge of establishing meaningful causal links, and the available archaeological repertoire, we are sceptical of approaches overreading the impact on aesthetic capacities or closely related phenomena—like creativity—of unique gene networks in our lineage (see Zwir et al., 2022). As we will argue, Neanderthals likely inherited the range of protoaesthetic abilities and related basic prerequisites from their ancient ancestors shared with the H. sapiens lineage. With the right protoaesthetic ingredients in place, crucial differences between the two species with respect to aesthetics would not lie in genetic endowment, but in sociocultural/environmental conditions for aesthetic experience and the production/selection of aesthetically-relevant items (and their successful preservation)—or the production and experience of other, more ephemeral behaviours, such as music and dance. Indeed, for Morley (2013) and Killin (2024), for example, it’s likely that Neanderthals would have inherited many of the features supporting musicality that evolved in the common ancestor of humans and Neanderthals. Thus, we do not believe that the biological differences between Neanderthals and modern humans are sufficient to support an inference to the lack of or a major constraint on Neanderthal aesthetic capacity.

2.5 Moving forward

It is important here to notice how arguments for scepticism reveal that much debate conceptualizes Neanderthals and their aesthetic abilities with reference to the upper limit of H. sapiens’ aesthetic repertoire: notably, fancy personal ornamentation, representational parietal paintings, and portable items like figurines. Think again of the iconic cave paintings of Lascaux, or Chauvet, or the finely crafted Lion-Man, Vogelherd Horse, and various Venus figurines (e.g., Conard, 2016). These meet a ‘high bar’, impressive also according to our own aesthetic sensibilities today, but do not exhaust ancient H. sapiens’ aesthetic activities. So, there’s a risk in assuming that these kinds of aesthetic behavioural products would have mattered to Neanderthals in the same way that they clearly mattered to ancient H. sapiens. This presupposition, we believe, still acquiesces in a corollary of the unfortunate dichotomy Wynn and colleagues warned their readers about—characterizing views of the Neanderthals as cognitively inferior to H. sapiens versus views of the Neanderthals as cognitively indistinguishable (Wynn et al., 2016). In the context of aesthetics, the use of a Sapiens-derived standard translates into the current impasse: we can either recognize the presence, or the lack of traits of our own aesthetic niche in Neanderthal archaeology. Either we praise them for sharing our aesthetic sensitivities and capacities, or we emphasize what is missing from their material worlds—usually, the most impressive aesthetic items of the Aurignacian repertoire. In either case, we would still be looking for traces of ourselves in Neanderthal worlds, failing to address the Neanderthal aesthetic sense in its own right.

So, as Wynn et al. (2016) claimed, Neanderthal cognition may well not be indistinguishable from, nor inferior to that of H. sapiens, but may be different. However, how to track this difference in the material record remains a complex problem—changes in the archaeological signal are not solely due to cognitive constraints, but crucially also to varying demographic, sociocultural, cooperative landscapes. In our view, this important assertion points to a missed opportunity: understanding the specificities of Neanderthal aesthetic practices, motives, and trajectories. The problem of determining the aesthetic status of items from long-gone social worlds without relying on modern aesthetic conceptions as a heuristic was at the centre of debates on the rehabilitation of aesthetic analysis in archaeology (see, e.g., Morphy, 1994; Renfrew, 1994; Smith, 1994; Gosden, 2001; Robb, 2017; Skeates, 2017). Here, we have the additional, comparative challenge of making inferences across species boundaries. While we are not the sole theorists to emphasize this interpretive impasse in Neanderthal archaeology (see Moro Abadía & Chase, 2021), much work is still needed to productively overcome it. Even when the risks of H. sapiens projection are acknowledged, striking a balance proves difficult. Understanding Neanderthal aesthetics by its own terms should not, we think, translate into an overall dismissive attitude toward evidence supporting shared behaviours between the two species, therefore turning our eyes blind to similarities (e.g., Slimak, 2023). It is an evolutionary approach that is most helpful in capturing differences against the backdrop of shared, evolved behaviours. We turn to this ‘Neanderthal challenge’ in Sect. 4.

For now, let’s briefly take stock of what our analysis of the sceptical arguments has taught us. Whether contesting the in-principle possibility of Neanderthal aesthetics, Neanderthal authorship of available evidence, Neanderthal spontaneous inventiveness, or frequent engagement with aesthetically-relevant items, we have shown that (i) the genetic/biological forcing objection (in its strong form) is theoretically and empirically weak; (ii) arguments can, at best, cast doubts on specific aesthetic items, but are ineffective against the broader available repertoire considered en masse; (iii) arguments are vitiated by a focus on the most extreme expressions of Homo sapiens aesthetic experience—essentially, what we all tend to consider today to be, from our vantage point, artistic expression (or something very near it). Although the preceding arguments may not have yet convinced our opponents of our positive claim, we believe that the standard arguments do not license a negative claim about Neanderthal aesthetic capacity.

In the following section, we show how scepticism against Neanderthal aesthetic capacity is further weakened by taking a phylogenetic, evolutionary perspective. We discuss considerations supporting the deeper roots of hominin protoaesthetic capacity within the Acheulean stone tool industry.

3 Wynn and Berlant’s analysis of the Acheulean ‘handaxe aesthetic’

Understanding the evolution of human cognition and culture requires grasping the range of abilities possessed by ancient hominin populations. Understanding the evolution of human aesthetically-relevant capacities is no different. Evolutionary cognitive archaeologists analyse the archaeological record via theories/models from the cognitive sciences that figure in their causal explanations. Cognitive archaeology is a multifaceted research program with a diversity of methodologies and modes of inference, although one common mode of inference is to posit capacity according to what is required, or likely required, for the production of archaeologically known artefacts (Currie & Killin, 2019; Killin & Pain, 2023). The general schema: according to (independently motivated theory/model) M, capacity X is required (or is very likely required, or is involved in the best explanation) for the production of artefact Z; therefore, since we see Z in the archaeological record at time t, we can infer X was in place by t.

Wynn and Berlant (2019) put this schema into action with respect to evolutionary aesthetics. We think their analysis is worth exploring at length, as they provide a persuasive line of reasoning for inferring protoaesthetic capacities deep in the Homo lineage. This is of course relevant for making the claim that these protoaesthetic abilities/sensitivities are likely homologous for Homo sapiens and the Neanderthals. The model in question is a reconstruction of the framework of Anjan Chatterjee and others (see, e.g., Chatterjee, 2014; Chatterjee & Vartanian, 2014, 2016), according to which there is no dedicated cognitive module for aesthetic cognition; aesthetic experience is a pluralistic category. Even so, the model decomposes aesthetic experience into three broad components: (i) sensorimotor/perceptual; (ii) emotional/valuation; (iii) meaning/knowledge. Here we focus on the first of these—the sensorimotor/perceptual—of which five key aspects include Gestalt form, peak shift, prototypicality, familiarity, and framing.¹² Each of these five features is taken to be central to (modern human) aesthetic experience. Central, rather than necessary conditions, and as such, might not be implicated in some particular aesthetic experiences. Yet, as central features, considered separately, they are (for Wynn and Berlant) among that which is required of an evolutionary account of aesthetics. These are the Xs in the above schema—finding trace evidence of them in early stone technologies thus stands to shed light on early aesthetic cognitive evolution.

Although intended more as a convenience than an ontological claim, we dub this ‘protoaesthetics’ for two pragmatic reasons.¹³ First, it involves only a subset of the features, or emerging/rudimentary variants, underwriting aesthetic behaviours. As we discussed in Sect. 1, some of these aesthetic behaviours are known of Neanderthals as well as of ancient H. sapiens. Second, it is focused on a time that is presumably prior to the evolutionary ‘coalescence’ of such capacities and sensitivities and their implication in other (i.e., non-tool-related) aesthetic purposes. Although our focus is on the sensorimotor/perceptual, it is assumed that positive affect is attached to these features (i.e., implicating the emotional/valuation component of the guiding framework), at least partially driving their occurrence.

Wynn and Berlant apply the inferential machinery discussed above to the Acheulean stone tool industry, the technocomplex associated with Homo erectus s.l. and Homo heidelbergensis, and preceded by the Oldowan (which consisted mostly of stone cobbles, cores, and flakes). The Acheulean dates back to 1.8 million years ago (Lepre et al., 2011), long preceding the H. sapiens/Neanderthal split, and includes such tools as the famous multifunctional, teardrop-shaped bifacial handaxes. Inferences made about Acheulean stone tools and their producers in the service of understanding complex human cognitive evolution, we point out, also serve our understanding of Neanderthals. For our purposes, this is especially the case when it comes to the early- to mid-Acheulean tools.

One point worth emphasizing in the context of current debates on aesthetic attributions is that direct archaeological evidence for paradigmatic ‘aesthetic’ activities only takes us back so far, while there is an abundance of stone tools from much deeper in time. So, Wynn and Berlant probe the stone tool record for trace evidence of the five aforementioned features of modern-day aesthetic experience. This involves probing the record for features of handaxes that were (presumably intentionally) imposed on the raw material during reduction, possibly were costly to impose, and while pleasing to behold, would not have impacted the utilitarian functionality of the tool.

From almost the very first appearance of handaxes, knappers appear to have exploited visual processing effects to produce pleasing results. In rough chronological order of their earliest clear appearance these visual effects were imposition of basic Gestalt forms, especially symmetry; peak shift, initially via size exaggeration; prototypicality via regularization of form; familiarity, as represented by community styles; and framing, use of the handaxe form to focus visual attention on inclusions. (Wynn & Berlant, 2019, pp. 284–285)

As these features do not show up all at once, but come and go at different times and in different places, they hint at a mosaic structure (Foley, 2012; Parravicini & Pievani, 2019) to aesthetic cognitive evolution.

Certain forms are pleasing to look at (Hodgson, 2009, 2011, 2015). They stimulate mu-opioid sensitive cell groups in the primary visual cortex. Neural processing of visual information takes place in the occipital lobes; its cell groups are sensitive to particular line/shape orientations, colours, and so on (Chatterjee, 2014; Chatterjee & Vartanian, 2014; Palmer et al., 2012). For example, the brain dedicates more neural resources to processing horizontal and vertical lines than oblique lines, and attaches positive affect to them. The brain then passes the visual information ‘forward’ for further processing and executive discrimination. Symmetry is one such pleasing-to-behold form. Acheulean handaxes all exhibit symmetry in a very rough sense due to their glob butt and other ‘design imperatives’ (Gowlett, 2006) that are diagnostic of the tool. Acheulean handaxes, however, that lack a high degree of symmetry can still be perfectly functional. And indeed the earliest known Acheulean handaxes, of roughly 1.8 mya, were merely roughly symmetrical (see Wynn & Berlant, 2019, p. 285). Yet over the long haul of the Acheulean, the producers of many Acheulean handaxes trimmed their axes so that the sides more closely mirrored each other, and it is rather telling, in our view, that it did not take long for this to begin (Diez-Martín et al., 2016).¹⁴ Figure 3 is a 1.7 million-year-old example.

Fig. 3

1.7 million-year-old Acheulean handaxe. A bifacially-flaked basalt handaxe—very large at 31 cm long—from FLK West, Olduvai Gorge (Tanzania). Image reproducible under the terms of the Creative Commons Attribution 4.0 International License. Diez-Martín et al. (2016)

A sensitivity to symmetry was not only expressed in handaxes, but also ‘spheroids’ (stone balls; Wynn & Berlant, 2019, p. 286), which currently date back to around 1.5 mya, although the purposes of the balls remain a matter of debate.

Peak shift (exaggerating features to extreme values for impact) is a key feature of much visual art today, for example, used to great comical effect in political satire. Not to mention the Venus figurines of the Upper Palaeolithic, with their large breasts, ample hips, and pronounced stomachs. The FLK West handaxe discussed above, Wynn and Berlant claim, is an early example of size exaggeration. At 31 cm long, the handaxe is not outside the range of the practically usable, but it is rather close. The idea: symmetry has a positive visual impact; relatively expanded symmetry has an even stronger visual impact. Other features too can be ‘peak shifted’ for visual effect: colour, texture, and so on. Olduvai Gorge at 1.4 mya saw knappers selecting sparkling quartz as a raw material for handaxes (Wynn & Berlant, 2019, p. 288). In Algeria, some Acheulean handaxes were made of strikingly patterned raw materials, or at least the raw material was reduced in such a way as to display those striking patterns in the product of the reduction/knapping process (Wynn & Berlant, 2019, p. 289).

A sensitivity to prototypical forms is a third feature of aesthetic experience today (Chatterjee, 2014; Palmer et al., 2012): “Prototypical forms are more visually pleasing than eccentric examples. To the trained, Western student of art a melted clock by Dali may be visually appealing, but this response depends on a specific cultural context, and is not a pre-attentive effect. In pre-attentive visual terms it is the prototypical clock that elicits the most positive affect” (Wynn & Berlant, 2019, p. 287). Prototypical forms also form the basis for comparison for recognising eccentric examples. Wynn and Berlant index prototypicality to regularisation of form: knappers achieved prototypicality by virtue of the regular production of hemilemniscate (teardrop/pear) shaped tools. Moreover, they demonstrate that peak shift may operate on prototypical features, generating examples of Acheulean handaxes with hypertrophic forms, for instance, the 660,000-year-old Gesher Benot Ya’aqov (Israel) handaxe (Goren-Inbar et al., 2002; Wynn & Berlant, 2019, p. 290), an elongated teardrop shape with a narrow tip.¹⁵

That which is familiar is often associated with positive affect (Chatterjee, 2014; Palmer et al., 2012), predicting the emergence of styles, even within teardrop prototypicality. Familiarity, as represented by community styles, is the hardest of these five features to document archaeologically. But at Boxgrove (500 kya) artefacts were preserved from a brief period, possibly a single generation (this inference is due to local circumstances: coastal landscape was briefly exposed and utilized by hominins before a rapid rise in sea level): “the handaxes are all very, very similar… a testament to the attractiveness of familiar patterns” (Wynn & Berlant, 2019, p. 288).

Paintings in art galleries are very often framed, drawing viewers’ attention to the content of the work within, and offering a separation between the work and the world. Movements in a classical music concert are ‘framed’ by moments of instrumental silence, directed by the conductor. Wynn and Berlant locate framing in the archaeological record by identifying examples of the use of the handaxe form to focus visual attention on the central axis of a particular axe with additional, non-utilitarian features, such as shells, crystals, or visually stimulating patterns created by holes in the raw material (such as face-like patterns: Wynn & Berlant, 2019, p. 292). A handaxe from West Tofts contains a well-preserved fossilized shell right in the centre of the front axe-face (Fig. 4; see also Wynn & Berlant, 2019, p. 291). By selecting a flint nodule that contained this shell and knapping around it, the producer of the handaxe was able to draw attention to the shell and accentuate its visual effect—plausibly, a very pleasing visual effect, as it is for us today.

Fig. 4

Source: Museum of Archaeology and Anthropology, University of Cambridge/Mark W. Moore, Museum of Stone Tools. URL = https://une.pedestal3d.com/r/EKNQYcekuv [Accessed 12 June 2024]

Flint Acheulean handaxe collected from West Tofts, Norfolk Country, England, in 1911; a fossil of a Cretaceous bivalve mollusc, Spondylus spinosus, is located centrally on one face. Image reproducible under the terms of Creative Commons by Attribution.

There is no reason to think that non-human primates make ‘protoaesthetic’ appraisals of their tools; they appear utterly indifferent to a tool’s visual appearance. And the early hominin toolmakers of the Oldowan industry may well have been ape-like in this respect too: the visual appearance (for its own sake) of a flake or a core or a hammer was irrelevant to task suitability. But, as Wynn and Berlant’s analysis shows, in time ancient knappers would “begin to attend more closely to features of cores as an aid to effective knapping, and such focused attention was an important prerequisite” (p. 292) of later developments. So-called ‘overdetermination’ is the earliest archaeologically visible hint of this:

As early as the handaxe from FLK West… a hominin knapper invested more time and energy to achieve a pleasing form than was necessary for its functionality. Why? At a minimum the knapper… made an appraisal about this artifact. Even a judgment as basic as ‘this pleases me’ is an aesthetic appraisal. And it clearly was not an appraisal of how well the tool might work (the knapper could certainly have made such a judgment as well), it was an appraisal of the form of the handaxe. (Wynn & Berlant, 2019, p. 292)

Some might question whether merely ‘this pleases me’ is sufficient for aesthetic appraisal, even on a broad notion, but in our view, the point stands with respect to what we’re calling protoaesthetic appraisal, a more rudimentary and partial conception of the phenomenon, given our incrementalism and evolutionary perspective. It is remarkable that this accompanies the production of some Acheulean handaxes almost from the get-go. Or perhaps it would be, if there were not already independent reasons for thinking that Acheulean technologies require, and thus reveal, cognitive upgrades in comparison to Oldowan technologies (Lepre et al., 2011; Stout, 2011; Stout et al., 2008, 2011, 2015).

In this section, we have outlined and advocated for a modest reading of Wynn and Berlant’s handaxe aesthetic analysis. The implications for considering the Neanderthals—not discussed by Wynn and Berlant (2019)—we believe, are reasonably clear.¹⁶ Many of the protoaesthetic capacities and sensitivities identified in the Acheulean record belong to the common ancestors of both H. sapiens and Neanderthals: it is far likelier that both species inherited the capacity for protoaesthetic appraisal than the alternative, namely, that although we inherited it, Neanderthals somehow lost it. The changing shape of the Neanderthal record, we believe, confirms this, as we suggest in Sects. 1 and 2 above. Indeed, the point remains, even if that ‘protoaesthetic package’ turns out to be slightly different from what Wynn and Berlant propose: new evidence, analyses, or theory might shake up how best to characterize the protoaesthetic components detectable in the Acheulean record. In the next section, we turn to the challenge of framing Neanderthal aesthetics, moving beyond the biased quest for features that characterize H. sapiens’ aesthetic experience.

4 Neanderthal aesthetics, on its own terms: towards a research program

Recall the false dichotomy we mentioned earlier: how do we navigate the still rather unexplored ‘third way’ beyond the inferiority and the indistinguishability theses? The problem—one might complain—is much easier to state than to solve. Clearly, there is no simple recipe for addressing this challenge. However, we do see two important avenues for progress, which we consider crucial guiding principles for future research.

One approach, as explored in the context of Acheulean handaxes, is to investigate and perhaps reconsider the minimum standards of evidence that archaeologists should meet in order to provision the inference that some artefact has an aesthetic character (or possesses aesthetic qualities, evinces an aesthetic sense). Explicit discussions about evidentiary aspects of reasoning in archaeology are particularly important, especially in light of the ongoing re-evaluation of Neanderthal archaeological repertoires. Indeed, borrowing Chapman’s and Wylie’s characterization, old data is constantly being mobilized as new evidence (Chapman and Wylie 2016; Wylie, 2017). The eagle talons from Krapina, Croatia, are a striking example in this sense, as the hypothesis of their use as personal ornaments emerged from a re-examination of previously known material, prompted by the recognition that raptors—particularly their claws and feathers—were important elements of the Neanderthal visual culture at other European sites (e.g., Fumane cave; Peresani et al., 2011). Further, reasoning about minimum evidentiary standards for assessing the aesthetic character of artefacts helps mitigate the risk of adopting double standards when analysing the material remains of various hominin groups, as the history of Neanderthal archaeology has abundantly shown (Roebroeks & Corbey, 2001). A second avenue for exiting the current impasse relates to the importance of putting coevolutionary frameworks to work. In particular, this means looking at the specific constraints of Neanderthal sociocultural worlds to understand how these shaped their aesthetic niches.

We next take each of these points in turn.

4.1 What counts as an aesthetic artefact?

Let’s take a closer look at the engraved giant deer phalanx from Unicorn Cave briefly mentioned in Sect. 2 (Fig. 5; Leder et al., 2021) as a recent instance of Neanderthal attribution and briefly see how practitioners inferred its status as an aesthetically-relevant item. This will provide a reference for discussing other elements of Neanderthal repertoires. Now, on what grounds do archaeologists claim that the Unicorn Cave phalanx is ‘more’ than a simple bone fragment? Several strategies come into play.

Fig. 5

51,000-year-old engraved giant deer phalanx from a late Middle Palaeolithic context at Einhornhöhle, Lower Saxony, Germany. Image reproduced with the permission of Springer Nature. From Leder et al. (2021)

The initial step in assessing the incisions is to determine if they were intentionally produced.¹⁷ This is achieved via micro-morphometric analyses (Fig. 6). Leder and colleagues have ruled out the possibility that the marks were butchering marks because the marks differ in location, depth, and profile from typical butchering-related cuts. Also, butchering marks are much more superficial, whereas these are 10 to 50 times deeper. And although deer was on the menu, toe phalanges are not particularly meaty. Moreover, these patterns exhibit a very systematic arrangement characterized by distinct lines and angles. Specifically, the six lines form five chevrons that intersect in sequence (see Fig. 6c), with angles rather narrowly ranging between 92.3 and 100.5 degrees (see Fig. 6d). These researchers, through experimental work, have inferred the specific movements involved, which included a particular series of both cutting and scraping actions, unlikely to be the unintended by-product of some other action. They also propose that the bone’s workability might have been enhanced by it being boiled once or twice (Leder et al., 2021, p. 1277). Among other observations called in support of the aesthetic character hypothesis is the fact that no obvious practical use can be inferred, although, with a touch of imagination, some have suggested a spool for a thread or a sinker for a fishing line (archaeologist John Shea, in Gershon, 2021). Another observation is tied to the rarity of giant deer at 55 − 35 kya north of the Alps, which according to the authors, supports the notion of a symbolic meaning (see Leder et al., 2021, p. 1277).

Fig. 6

Greyscale images were generated via micro-CT scanning: (a) close-up view of individual engravings; (b) blank view of the engraved side; (c) line interpretation and line numbers; (d) surface angles between individual lines; (e) line lengths. Image reproduced with the permission of Springer Nature. From Leder et al. (2021)

This, we think, is a rather paradigmatic reasoning strategy employed by practitioners to infer the aesthetic character of an artefact. Archaeologists leverage a series of epistemic resources (morphometric analyses, experimental data, palaeoecology, etc.) to assess two primary aspects: (i) that the object (its surface, in this case) was intentionally altered to obtain a perceptual effect (in this case, a visual pattern) not directly explained by any functional need; and (ii) the modifications manifest its makers’ qualities and skills.

Two critical points are worth making here. First, we think it is important to underline, once again, that inferring an object’s aesthetic character need not require excluding functionality/utilitarian uses, but nonetheless, providing evidence that function cannot entirely account for the objects’ distinctive features is indicative of an aesthetic role/aspect. As we saw in Sect. 3, some Acheulean handaxes are fashioned in a way that goes beyond simply making them fit for butchering and skinning game or cutting wood and plants—they are ‘overdetermined’ for their purposes. While this may already be a well-trodden trope among evolutionary aestheticians, in practice functional and aesthetic explanations are often treated as disjoint. In debates concerning Neanderthal aesthetic capacities, much attention is usually dedicated to ruling out a functional or utilitarian story of newly retrieved or reinterpreted artefacts all considered. This theoretical commitment is misplaced and off the mark. Regarding the deer phalanx, we would welcome the discovery that it’s a spool, but even so, it would be an exceptionally good-looking one. Its appearance, we suggest, would have been pleasing to the makers and users of it, who of course come equipped with the protoaesthetic starter-kit in place prior to the divergence of humans and Neanderthals.

Second, as tracing aesthetic attributes involves identifying makers’ skills and qualities (Currie, 2016), it is crucial to emphasize that this need not be reduced to technical virtuosity. Reducing the assessment of ‘the aesthetic’ solely to technical prowess (expressed at its peak in representational cave paintings, statuettes, bird-bone and mammoth-ivory flutes/pipes) has been a glaring source of human-facing bias that has plagued the interpretation of much Neanderthal material culture, in which genuinely aesthetic objects have likely been undiagnosed as such. Indeed, more likely, they were dismissed as not technically (or aesthetically/artistically) impressive according to our modern human perspective. One may point out that the Unicorn cave phalanx is not as technically impressive as signature Upper Palaeolithic engraved objects (such as the Lion Man), and may be tempted to challenge its status as an aesthetic object on this ground. But maker’s qualities relevant to aesthetic artefacts can be also investigated in terms of the manifestation of personal taste and time or resource investment, no matter how impressive we today judge the final result to be. That point is just as true of contemporary art today. In the case of the deer phalanx engraver—and not so differently from the meticulous Acheulean knapper—the act of selecting that specific body part from such a majestic animal, disarticulating it, potentially boiling it multiple times, and meticulously engraving it all indicates an investment of time and resources ultimately aimed at making an artefact at least partially for appraisal. Thus, in our view, this provides one window into the deep past of the realm of aesthetic capacities and sensibilities.

4.2 Framing the Neanderthal aesthetic niche(s)

Here’s a look into the future of this debate: when Neanderthals’ repertoires are evaluated against minimal (and explicit!) criteria for aesthetic attribution, as we suggested, the breadth and specificities of their aesthetic trajectories become apparent. One challenge, of course, is identifying appropriate criteria, although there is much to recommend the idea that this enterprise will be rather a local one (case-by-case). The criteria that were relevant in assessing the deer phalanxes in Sect. 4.1 will differ from those appropriate for assessing the use of ochre, for example.

If we look at Neanderthal repertoires from this relatively minimal, unbiased standard, there is, for instance, a whole culture that relates to pigment processing that emerges (and which, again, plausibly has deep hominin evolutionary roots: see Barham, 2002 for discussions of H. heidelbergensis use of pigments at Twin Rivers, Zambia). (Note that we are not talking about its possible symbolic meaning here, which is an orthogonal debate.) This is an interesting place to start to understand Neanderthal engagement in materiality for aesthetic purposes, as it shifts the discussion from one-off, potentially idiosyncratic, and controversial artefacts. And potentially, it can provide a less biased ground for comparisons with Homo sapiens’ practices and preferences. Although often assumed primarily as a visual activity, it is possible that ochre application could have been (e.g.) primarily haptic, but that need not discount its status as the product of aesthetically-charged activities.

As Wragg Sykes (2020) recounts, the past decade has seen a ‘pigment boom’ in Neanderthal archaeology. Their apparent interest in colour and mineral pigment processing is now well-evidenced at over 70 European sites. Here, pigments with colours ranging from blacks, to yellows, oranges, and reds are found. At Pech-de-l’Azé, in the Dordogne (southern France), for example, around 500 small pieces of manganese dioxide are known, half of which show signs of use-wear (d’Errico & Soressi, 2002; Rendu, 2010). Practical purposes of such minerals cannot be excluded: their uses could have included insect repellent, sunscreen, hair management, camouflage, fire ignition, or antiseptics. But as mentioned earlier, putative utilitarian uses shouldn’t constitute an issue for an aesthetic analysis. In fact, there is sensible evidence of choosiness, effort, and a sense of taste being invested in the collection and creative engagement with mineral pigments that warrants an extra-utilitarian story. This includes the collection and transportation of pigments from long distances (over 40 km, as shown by red ochre use at Maastricht Belvedere; Roebroeks et al., 2012), skillful experimentation and mixing of colours with sparkly rocks to obtain visual effects (Zilhão et al., 2010), shifts in colour uses potentially reflecting cultural changes (Dayet et al., 2019), and the application of pigment to objects such as marine shells or eagle talons (Zilhão et al., 2010; Radovčić et al., 2020; Peresani et al., 2013). All this speaks, in our view, to pigment use being a visually-oriented activity.

Here’s how a tiny fossil shell—one from marine gastropod Aspa marginata from Fumane cave—can tell an interesting story. In that area of Italy, the nearest fossil exposure with Aspa marginata shells is more than 100 km from the cave. Microscopic analysis of the shell’s outer surface revealed that it was smeared with a pure, finely ground, hematite powder, probably mixed with a liquid (Peresani et al., 2013). The pigment was sourced from one of the quarries located between 5 and 20 km away from the cave. Use-wear analysis indicates that the shell was likely perforated and probably used as an ornament, before being lost, discarded, or intentionally left at the cave. So, here we have a fossil shell (therefore, not food waste), that was noticed by a Neanderthal, collected and transported for a long distance (or perhaps even traded), and treated with specially sourced and prepared pigment. Lots of time and energy went into such a small object. This suggests that the deliberate collection and manipulation of ‘exotic’ objects via the use of pigments was a component of Neanderthal lifeways.

Neanderthals’ interest in colour, and probably in some specific colours, is also evidenced by their interest in raptors and corvid feathers and claws. In particular, an analysis of 1699 Palearctic Pleistocene sites showed an over-representation of species with black or dark remiges (wing feathers) when compared to sites with no human presence (Finlayson et al., 2012; Finlayson & Finlayson, 2016). Given that colour is a central feature of any human visual culture, analyses of Neanderthal pigment use and practices can offer an interesting lever for constructing a space of comparative aesthetics.

Before concluding, recall an issue we briefly raised in Sect. 1.4, the comparative scarcity of personal ornamentation at Neanderthal sites, relative to anatomically modern human sites. Different explanations can in principle account for the observed signal, from cognitive hypotheses, to sociocultural ones, to (more unlikely) hypotheses centred on systematic biases of asymmetric preservation. Regardless of the hypothesis we might want to test, however, we think it is crucial to frame Neanderthal material engagement via a coevolutionary approach. This is the second avenue we suggest for exploring the neglected ‘third way’ in Neanderthal archaeology.

The investment in specific material aesthetic practices, like personal adornment, and patterns of formal variability (style) are thought to be a response to social complexity and a means of mediating relations in cooperative networks (Straffon, 2016, 2019). When it comes to ornaments, it has been noted that Neanderthal repertoires show a rather local and unique character: “Many expressions of personal ornamentation are entirely unique, such as animal teeth or a marine shell with incisions (rather than perforations) for suspension, eagle talons hung as ornaments, or the use of feathers” (Spikins et al., 2017, p. 139). This would stand in contrast with patterns of similarity and larger-scale stylistic coherency among Aurignacian Homo sapiens’ repertoires (for instance, their shell beads or split based bone points). But it would be unwise to not consider these signals in the context of the horizon, structure, and degree of connectivity within Homo sapiens and Neanderthal metapopulations, respectively. One population might have a more ‘individualized’ aesthetic, and if so, that would be interesting to know. With Neanderthals, there’s now robust evidence of a distinctive demography: small effective population sizes (Prüfer et al., 2014), with band sizes at the lower limit of hunter-gatherer variability (Hayden, 2012), a high degree of within-band relatedness (Skov et al. 2022), and very limited large-scale social interactions (Pearce and Moutsiou, 2014). Although these features would have still allowed identity-conscious communities to form, Neanderthal societies might have generally been, as Spikins et al. put it, ‘inwardly focused’, with an ‘intimate sociality’ dependent on groups of close kin, with infrequent long-range connections and aggregations. It should be expected, then, that some items would be differentially explored in Neanderthal societies. Pearce and Moutsiou speculate about a different requirement of cultural supports ensuring connectivity over very long distances, such as ornaments and figurines, in worlds with frequent face-to-face interactions and thus not requiring a significant engagement in practices for maintaining networks in absentia.

To conclude, it takes a change in perspective not to investigate evidence of Neanderthal lifeways under the lamppost of modern human sensitivities. But constructing a space for comparative aesthetics is a valuable endeavour. After all, we are the only representatives of Homo left around. However, this should not imply playing the ‘high-bar’ game or projecting our tastes onto Neanderthal worlds. Fortunately, the way has been paved, making the journey all the more captivating.

5 Conclusions

In this article, we’ve argued that one shouldn’t bet against Neanderthal aesthetic capacity, but for it. No sceptical line of reasoning ultimately provides adequate provision for ongoing reluctance to posit Neanderthal aesthetic capacity, let alone a knockdown argument against such capacity, both for theoretical reasons and due to accumulating counterevidence. In addition to addressing immediate concerns with each argument, by identifying questionable theoretical commitments and acknowledging emerging counterevidence, we also drew attention to a common underlying bias that limits research in exploring more productive avenues: the persistent quest for features that capture our species’ aesthetic expression and aesthetic experience, within Neanderthal repertoires. In other words, Neanderthals may not have been indistinguishable from that of ancient H. sapiens, but nor were they necessarily inferior. So, we should not be surprised if the search for Neanderthal aesthetic practices suggestive of an aesthetic sense requires taking a different route, at least sometimes, to the search for (paradigmatic examples of) human aesthetic practices.

An evolutionary framing of the emergence of ‘protoaesthetic’ capacities and sensitivities among the common ancestors shared with H. sapiens—the makers of the Acheulean handaxes—provides an additional parsimony argument against the loss of such features in the Neanderthal lineage. The Acheulean stone tool industry contains clues of an incremental, evolutionarily developing protoaesthetic capacity/sensitivity, and just as H. sapiens have inherited this ‘protoaesthetic package’ from their H. erectus s.l. ancestors, so would have the Neanderthals. We also showed how scepticism against Neanderthal aesthetic abilities is still vitiated by a focus on high-profile expression of the human aesthetic repertoire, ultimately compromising the opportunity to understand the specifics of Neanderthal aesthetic trajectory in its own right. This impasse can be resolved, we’ve argued, by formulating minimum evidential standards for aesthetic attributions (especially in view of the ongoing reassessment of available evidence) and by putting coevolutionary frameworks to work to explain the differential expression of some aesthetic items (e.g., personal ornamentation). Investigating Neanderthal aesthetics on its own terms promises to be a generative and fruitful research program.