Animal Cognition

, Volume 22, Issue 2, pp 187–198 | Cite as

Absolute brain size predicts dog breed differences in executive function

  • Daniel J. HorschlerEmail author
  • Brian Hare
  • Josep Call
  • Juliane Kaminski
  • Ádám Miklósi
  • Evan L. MacLean
Original Paper


Large-scale phylogenetic studies of animal cognition have revealed robust links between absolute brain volume and species differences in executive function. However, past comparative samples have been composed largely of primates, which are characterized by evolutionarily derived neural scaling rules. Therefore, it is currently unknown whether positive associations between brain volume and executive function reflect a broad-scale evolutionary phenomenon, or alternatively, a unique consequence of primate brain evolution. Domestic dogs provide a powerful opportunity for investigating this question due to their close genetic relatedness, but vast intraspecific variation. Using citizen science data on more than 7000 purebred dogs from 74 breeds, and controlling for genetic relatedness between breeds, we identify strong relationships between estimated absolute brain weight and breed differences in cognition. Specifically, larger-brained breeds performed significantly better on measures of short-term memory and self-control. However, the relationships between estimated brain weight and other cognitive measures varied widely, supporting domain-specific accounts of cognitive evolution. Our results suggest that evolutionary increases in brain size are positively associated with taxonomic differences in executive function, even in the absence of primate-like neuroanatomy. These findings also suggest that variation between dog breeds may present a powerful model for investigating correlated changes in neuroanatomy and cognition among closely related taxa.


Cognitive evolution Brain evolution Brain size Executive function Breed differences Citizen science 



We thank Laurie Santos, Richard Wrangham, David Ivy, Eliot Cohen, Kip Frey, and all other members of the team for their help in the creation of; Adam Boyko, Martin Schmidt, and James Serpell for sharing data used in this project; Stacey Tecot and David Raichlen for valuable feedback on previous drafts; and especially all of the dog owners who participated in experiments as citizen scientists.

Author contributions

BH, JC, JK, ÁM, and ELM conceived and designed the experiments. DJH and ELM analyzed the data. DJH, BH, JC, JK, ÁM, and ELM wrote the paper.


DJH was supported by an Emil W. Haury Fellowship from the School of Anthropology at the University of Arizona, and a Graduate Access Fellowship from the Graduate College at the University of Arizona. ÁM was supported by the Hungarian Academy of Sciences (MTA-ELTE Comparative Ethology Research Group, MTA 01 031).

Compliance with ethical standards

Conflict of interest

BH is a founder of and a member of its Scientific Advisory Board. JC, JK, and ÁM are also members of the Scientific Advisory Board.

Data accessibility

Data are available as electronic supplementary material.

Ethical standards

All animals included in this study were pet dogs tested by citizen scientists in their own homes. The use of third-party data from was approved by Duke University IACUC protocol A138-11-06 and data were collected in accordance with relevant guidelines and regulations.

Supplementary material

10071_2018_1234_MOESM1_ESM.docx (895 kb)
Supplementary material 1 (DOCX 894 KB)
10071_2018_1234_MOESM2_ESM.xlsx (26 kb)
Supplementary material 2 (XLSX 26 KB)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.School of AnthropologyUniversity of ArizonaTucsonUSA
  2. 2.Department of Evolutionary AnthropologyDuke UniversityDurhamUSA
  3. 3.Center for Cognitive NeuroscienceDuke UniversityDurhamUSA
  4. 4.Department of Developmental and Comparative PsychologyMax Planck Institute for Evolutionary AnthropologyLeipzigGermany
  5. 5.School of Psychology and NeuroscienceUniversity of St AndrewsSt AndrewsUK
  6. 6.Department of PsychologyUniversity of PortsmouthPortsmouthUK
  7. 7.Department of EthologyEötvös Loránd UniversityBudapestHungary
  8. 8.MTA-ELTE Comparative Ethology Research GroupBudapestHungary

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