There are two dominant theories of the origins of the Indo-European languages; the Pontic-Caspian-Steppe hypothesis and Anatolian hypothesis. The first of these locates the original speakers of Proto-Indo-European on somewhere on the Russian steppes, north of the Caspian Sea and posits a point of separation at around 3500–4500 BCE. This connects the Proto-Indo-European language with the Yamnaya horizon and in doing so suggests a bridge between linguistic and archaeological data. The Yamnaya horizon is an archaeological culture associated with kurgan cemeteries (tumulus burial mounds), corded-ware pots, and a system of nomadic pastoralism. This last point is of importance for the Steppe (and any other) hypothesis as some motivation is required for other cultures to adopt the Indo-European languages. Language displacement is often associated with some kind of social and technological advance and a prominent element of the Steppe hypothesis is the idea that the Proto-Indo-European language spread with nomadic pastoralism. Without some material basis in the archaeological data, it is difficult to construct a plausible narrative for widespread social change. Influential defenders of this claim are Marija Gimbutas and David Anthony.
The alternative theory locates the Indo-European homeland (Urheimat) in modern-day Turkey and suggests a point of divergence at around 7000–6000 BCE (the Early Neolithic). In this case, the socio-technological development spurring the spread of Proto-Indo-European is the development of agriculture. The displacement of earlier non-Indo-European languages was facilitated by both the population increase enabled by farming and the prestige attached to farming cultures. An advantage of this hypothesis is that the spread of farming techniques has been well-documented by archaeologists. This theory was propounded by the archaeologist Colin Renfew and is supported by Grey and Atkinson (2003) and Bouckaert et al. (2012).
Both of these hypotheses have the virtue of identifying a relatively central area from which the Indo-European languages could have spread as well as having archaeologically attested mechanisms for this spread (pastoral nomadism or agricultural expansion). However, since the Proto-Indo-Europeans are fundamentally a linguistic posit, this is not a debate that can be decided by archaeological evidence alone. At the very least, a broad interdisciplinary approach is required. Which disciplines are invited to the table, however, remains a contested issue. Recent genetic data appears to support the Steppe hypothesis by confirming migrations from the steppes (Haak et al. 2015).Footnote 8 On the other hand, Bayesian phylogeographic methods support an Anatolian origin (Bouckaert et al. 2012).Footnote 9
A chief point of contention between proponents of each theory is whether linguistic palaeontology is a legitimate methodology. Renfrew writes ‘[t]he main reason for the failure to locate such a homeland arises, I think, first from an unwise reliance on linguistic palaeontology in a rather uncritical way’ (Renfrew 1987, pp. 97–98). In contrast, Robert Beekes, a linguist rather than an archaeologist, summarises Renfrew’s position as follows: ‘His theory happens to be contradicted by the linguistic and historical data which we have at our disposal, which is the reason why he must reject all the conclusions which have been reached by linguistic palaeontology’ (Beekes 2011, p. 50). We have an instance here of a debate between archaeologists such as Renfrew and Anthony which hinges in large part on the legitimacy of linguistic palaeontology as a method.
The claims made for linguistic palaeontology can appear quite extreme. For example, Anthony writes: ‘The proto-lexicon contains much more, including clusters of words, suggesting that the speakers of PIE inherited their rights and duties through the father's bloodline only (patrilineal descent); probably lived with the husband's family after marriage (patrilocal residence); recognized the authority of chiefs who acted as patrons and givers of hospitality for their clients; likely had formally instituted warrior bands; practiced ritual sacrifices of cattle and horses; drove wagons; recognized a male sky deity; probably avoided speaking the name of the bear for ritual reasons; and recognized two senses of the sacred (“that which is imbued with holiness” and “that which is forbidden”). Many of these practices and beliefs are simply unrecoverable through archaeology’ (Anthony 2007, p. 15).Footnote 10
Gimbutas, appealing to mythology and material culture as well as linguistics, goes further when discussing the cultural change enforced by Indo-European expansion: ‘These changes were expressed as the transition from matrilineal to patrilineal order, from a learned theocracy to a militant patriarchy, from a sexually balanced egalitarian society to a male-dominated hierarchy, and from a chthonic goddess religion to the IE sky-oriented pantheon of gods’ (Gimbutas 1993, p. 219). Others have argued that a ‘democratic revolution’ in the centre of the Indo-European linguistic sphere accounts for the absence of cognates for ‘king’, *rēǵs in certain languages (discussed in Mallory 1976, p. 53).
These are clearly very strong conclusions to derive from linguistic evidence and it is understandable that critics would be suspicious. Rather than try to justify the strongest claims about the cultural reconstruction of prehistorical societies, I will confine my focus here to weaker claims which bare more directly on archaeological data; claims about the homeland of speakers of the proto-language. It is the homeland question that can have the greatest relevance for archaeology because it is through identifying a homeland that researchers are able to connect a language with a particular material culture. This isn't to deny that linguists may practice semantic reconstruction with other interests. But we don't need to vindicate the strongest claims made by the proponents of linguistic palaeontology in order to assess its value. While this focus may not be expansive enough for either Anthony (or Nietzsche), it seems to be the most defensible use of the method and the most directly relevant to archaeologists.
Before we continue, certain familiar caveats are required. The acceptance of the claim that Indo-European languages share a common ancestor does not commit one to the idea that there ever existed a homogeneous material culture or a unified linguistic community that spoke it. These ideas might be motivated by further archaeological evidence but the linguistic evidence does not compel them. Similarly, talk of a ‘homeland’ must be shorn of nationalist connotations. The homogeneity enforced, often violently, by the modern nation-state shouldn't be projected upon prehistoric communities. There is little reason to believe that speakers of a proto-language, in virtue of sharing reconstructed linguistic items, considered themselves to be a single political community or that they maintained rigid borders with other communities. Furthermore, when dating the spread of these languages, the presence of reconstructions, particularly of terms referring to technological advances, does not tell us that the language or community sprang into existence at the same point in time that the technology did. If future linguists managed to reconstruct the word ‘internet’, they would be wrong to infer that the English language came into existence around the turn of the second millennium. What such a reconstruction might indicate is that the word was in use prior to the division of the proto-language into various families. A linguistic homeland is an essentially temporal notion.
My aim is to make a distinction between practical and principled concerns with linguistic palaeontology. Practical objections concern the details of specific reconstructions and can be responded to (though may not be unanimously resolved) within a shared theoretical framework. Some of these will be discussed in the following. Principled objections are directed to the fundamental assumptions of the framework. I will argue that some of these do successfully undermine a particular way of thinking about LP but shouldn't lead us to throw the baby out with the bathwater.
To assess things, we need an account of the standard model of linguistic palaeontology. The claim that ‘a community's culture is reflected in its language’ (Bostoen 2007, p. 175), is intuitively plausible but how this can be turned into a scientific methodology is our focus here.Footnote 11 Specifically we must ask, what is the form of inference made by linguistic palaeontologists? The bluntest formulation suggests we can infer what objects existed in an environment from semantic reconstructions:
Reconstruction entails Referent: ‘It is fair to assume that the things which the reconstructed words represent also actually existed’ (Beekes 2011, p. 35).Footnote 12
If this were the form of inference, it wouldn't be warranted. We can't infer directly from the existence of a reconstructed meaning to the existence of its referent. Some of the best-attested PIE expressions concern various gods while the present English language contains the words ‘unicorn’ and ‘dragon’. Although the inference is commonly stated this way, it's best to take this as loose writing and not what proponents of LP actually believe. To handle mythological cases, some intermediary step is needed. A more plausible inference is:
Reconstruction entails Concept: ‘If a word can be confidently reconstructed to the protolanguage (crucially, in both form and meaning), we may conclude that the concept it designates was known to the speakers of the protolanguage’ (Epps 2015, p. 580).
This is much more plausible. However, I think it can do with a bit of revision as it can be jarring to say that words designate concepts since most of our talk is about objects in the world rather than our concepts themselves. Further, if you have a psychological theory of what concepts are, you might rightly be wary of the idea that we can uncover the psychological states of speakers of a proto-language from LP. It would be helpful to introduce the Fregean terminology which is commonly applied in the philosophy of language. According to Frege, a word expresses a sense which determines a reference. While the reference of an expression can be an object in the world, a sense is simply a mode of presentation of that reference; one referent can be picked up by multiple senses. For example, it is conceivable that the terms *kwékwlos and *rot-eh2- were used to refer to the same objects, wheels, but had different senses.
Now we can state the form of inference. Semantic reconstruction allows us to reconstruct the senses of expressions in the lexicon. If we can reconstruct the sense, then assuming that the expression doesn't explicitly concern some mythological being, we can infer that the speakers of the proto-language were acquainted with the object referred to, its reference. We can then use these referents to determine the homeland of the proto-language. The homeland will be a region in which these objects existed.
This method hasn't been confined to the question of the Indo-European homeland. Siebert (1967) placed the Algonquian homeland to the north of Lake Ontario based on shared names for biological species like ‘seal’ while others place it to the west of Lake Superior. Similarly, the reconstruction of a word for ‘crocodile’ is used to rule out Polynesia as an origin for Proto-Austronesian (Crowley and Bowern 2010, p. 312). The same methodology has also been applied to determine the origin of the Bantu languages.Footnote 13 Much of what is known about the origins of the Romani people is determined by historical linguistics (Campbell 1998, pp. 73–74). The presence of loan words in the Romani languages tells the story of when the Romani left Indian and passed through Persian and the Byzantine empire into the west. For a critical account of the use of linguistic methods for Northern Fennoscandian prehistory, see Saarikivi and Lavento (2012).