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The social and cultural roots of whale and dolphin brains

An Author Correction to this article was published on 05 December 2017

This article has been updated


Encephalization, or brain expansion, underpins humans’ sophisticated social cognition, including language, joint attention, shared goals, teaching, consensus decision-making and empathy. These abilities promote and stabilize cooperative social interactions, and have allowed us to create a ‘cognitive’ or ‘cultural’ niche and colonize almost every terrestrial ecosystem. Cetaceans (whales and dolphins) also have exceptionally large and anatomically sophisticated brains. Here, by evaluating a comprehensive database of brain size, social structures and cultural behaviours across cetacean species, we ask whether cetacean brains are similarly associated with a marine cultural niche. We show that cetacean encephalization is predicted by both social structure and by a quadratic relationship with group size. Moreover, brain size predicts the breadth of social and cultural behaviours, as well as ecological factors (diversity of prey types and to a lesser extent latitudinal range). The apparent coevolution of brains, social structure and behavioural richness of marine mammals provides a unique and striking parallel to the large brains and hyper-sociality of humans and other primates. Our results suggest that cetacean social cognition might similarly have arisen to provide the capacity to learn and use a diverse set of behavioural strategies in response to the challenges of social living.

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Fig. 1: Distribution of residual brain size and social repertoire scores.
Fig. 2: Mid-sized social groups are associated with larger brain size and higher social repertoire scores.
Fig. 3: Model of likely relationships between brain size, behaviour and ecology in cetaceans. Paths were determined via a model selection approach using AIC.

Change history

  • 05 December 2017

    In Table 1 of the Supplementary Information, the data presented in the column ‘Corrected social repertoire’ were incorrect. This error does not affect the analyses, statistics or conclusions of the study, which employed the correct values. The data have now been corrected in the Supplementary file.


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We thank R. Sears of the Mingan Island Cetacean Study for early encouragement of this work. K.C.R.F. is supported by a postdoctoral fellowship from the Natural Sciences and Engineering Research Council of Canada; S.S. is supported by a Royal Society University Research Fellowship (UF110641).

Author information




K.C.R.F., M.M. and S.S. conceived the project and wrote the manuscript. K.C.R.F. and M.M. collated the data, with some assistance from S.S. S.S. primarily conducted statistical analyses, with some assistance from M.M. and K.C.R.F.

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Correspondence to Susanne Shultz.

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Supplementary Information

Supplementary Figures 1–7; Supplementary Tables 3–8.

Supplementary Table 1

Main database of basic cetacean physical and social data.

Supplementary Table 2

Database of cetacean social and prosocial behaviour.

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Fox, K.C.R., Muthukrishna, M. & Shultz, S. The social and cultural roots of whale and dolphin brains. Nat Ecol Evol 1, 1699–1705 (2017).

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