Trends in Cognitive Sciences
ReviewExplaining brain size variation: from social to cultural brain
Section snippets
The social brain
It has long been known that various mammalian and bird lineages differ in brain size, relative to body size 1, 2. The most widely accepted explanation is known as the Machiavellian intelligence [3] or social brain hypothesis [4]. Developed to explain variation order in relative brain size among mammalian orders and within primates, the hypothesis argues that large brains are adaptations for dealing with the complexities of social life. Several studies have documented the remarkably
Grade shifts and the social brain
For some species or lineages, the social brain hypothesis does a poor job of predicting their brain size. On the one hand, orangutans (Pongo spp.) or aye-ayes (Daubentonia madagascariensis) live in socially simple societies but nonetheless have larger brains than related primates living in far more complex societies [19]. On the other hand, some relatively small-brained taxonomic groups have better socio-cognitive abilities than expected on the basis of their brain size, a phenomenon known as
Domain-specific or domain-general cognitive abilities?
The second problem with the social brain hypothesis is the growing evidence for a non-modular, general intelligence: an overarching ability to respond flexibly to new or complex situations, to learn and to innovate. Studies reviewed in Box 2 support the idea that general intelligence is not a uniquely derived human trait but instead a phylogenetically old phenomenon, found among primates, rodents and birds.
Parallel emergence of abilities in multiple domains is not explained by the social brain
A cultural rather than just social brain
The existence of domain-general cognitive abilities in larger-brained birds and primates is incompatible with the social brain hypothesis. However, it is entirely consistent with Reader and Laland's [32] proposal that general behavioral flexibility, not tied to any domain in particular (i.e. content-neutral), is the adaptation underlying cognitive performance in primates. For some reason, however, this idea did not become as popular as the social brain hypothesis, despite its strong explanatory
Concluding remarks
In conclusion, we noted two weaknesses in the social brain hypothesis: it cannot account for the presence of domain-general cognitive abilities in birds and mammals, and it leaves grade shifts in brain size unexplained.
Unexplained grade shifts can have thee causes. First, some filter (e.g., due to small body size or high unavoidable mortality) may prevent the evolution of a larger brain, even though selection would in principle favor improved socio-cognitive abilities. Second, the taxon's high
Acknowledgments
The research reported here was supported by the Swiss National Fund (SNF-grant nos 105312-114107, 31003A-111915, 31003A-117789 and 310030-13083). We thank Sonja Koski, Caroline Schuppli, Michèle Schubiger and three anonymous reviewers for valuable comments.
References (105)
False-belief understanding in infants
Trends Cogn. Sci.
(2010)Strong and consistent social bonds enhance the longevity of female baboons
Curr. Biol.
(2010)Questioning the social intelligence hypothesis
Trends Cogn. Sci.
(2007)Cleaner wrasses Labroides dimidiatus are more cooperative in the presence of an audience
Curr. Biol.
(2011)The conditions for tool use in primates: implications for the evolution of material culture
J. Hum. Evol.
(1999)- et al.
Chimpanzee tool technology in the Goualougo Triangle, Republic of Congo
J. Hum. Evol.
(2007) - et al.
Social cognition
Curr. Biol.
(2006) Flexible remodeling of organ size during spring migration of the garden warbler (Sylvia borin)
Zoology (Jena)
(2005)- et al.
Sociality, evolution and cognition
Curr. Biol.
(2007) A comparison of bonobo and chimpanzee tool use: evidence for a female bias in the Pan lineage
Anim. Behav.
(2010)
Costs of encephalization: the energy trade-off hypothesis tested on birds
J. Hum. Evol.
The expensive brain: a framework for explaining evolutionary changes in brain size
J. Hum. Evol.
Life history costs and benefits of encephalization: a comparative test using data from long-term studies of primates in the wild
J. Hum. Evol.
Big-brained people are smarter: a meta-analysis of the relationship between in-vivo brain volume and intelligence
Intelligence
Complex relationship between multiple measures of cognitive ability and male mating success in satin bowerbirds, Ptilonorhynchus violaceus
Anim. Behav.
Wild chimpanzees rely on cultural knowledge to solve an experimental honey acquisition task
Curr. Biol.
Evolution of Brain and Intelligence
Brains, innovations and evolution in birds and primates
Brain Behav. Evol.
Machiavellian Intelligence: Social Expertise and the Evolution of Intellect in Monkeys, Apes and Humans
The social brain hypothesis
Evol. Anthropol.
The adaptive value of sociality in mammalian groups
Philos. Trans. R. Soc. B: Biol. Sci.
Cognitive adaptations of social bonding in birds
Philos. Trans. R. Soc. B: Biol. Sci.
The evolution of animal ‘cultures’ and social intelligence
Philos. Trans. R. Soc. B: Biol. Sci.
Evolution in the social brain
Science
On pedagogy
Dev. Sci.
Humans have evolved specialized skills of social cognition: the Cultural Intelligence Hypothesis
Science
Origins of Human Cooperation
The social brain: mind, language, and society in evolutionary perspective
Annu. Rev. Antrhopol.
Social bonds in birds are associated with brain size and contingent on the correlated evolution of life history and increased parental investment
Biol. J. Linn. Soc.
The benefits of social capital: close social bonds among female baboons enhance offspring survival
Proc. R. Soc. B
The evolutionary origins of friendship
Annu. Rev. Psychol.
Encephalization is not a universal macroevolutionary phenomenon in mammals but is associated with sociality
Proc. Natl. Acad. Sci. U.S.A.
Machiavellian intelligence
Evol. Anthropol.
Fish cognition: a primate's eye view
Anim. Cogn.
Human universals and primate symplesiomorphies: establishing the lemur baseline
Bats are able to maintain long-term social relationships despite the high fission-fusion dynamics of their groups
Proc. R. Soc. B
Overall brain size, and not encephalization quotient, best predicts cognitive ability across non-human primates
Brain Behav. Evol.
The evolution of primate general intelligence
Philos. Trans. R. Soc. B: Biol. Sci.
Forest chimpanzees (Pan troglodytes verus) remember the location of numerous fruit trees
Anim. Cogn.
Foraging cognition in nonhuman primates
Social intelligence, innovation and enhanced brain size in primates
Proc. Natl. Acad. Sci. U.S.A.
Principles of Brain Evolution
Bigger is not always better: when brains get smaller
Biol. Lett.
Life history and cognitive evolution in primates
Evolving Brains
Anatomical and histological changes in the alimentary tract of migrating blackcaps (Sylvia atricapilla): a comparison among fed, fasted, food-restricted, and refed birds
Physiol. Biochem. Zool.
Experimental evolution of aging, growth, and reproduction in fruitflies
Proc. Natl. Acad. Sci. U.S.A.
Effects of seasonality on brain size evolution: evidence from strepsirrhine primates
Am. Naturalist
Arboreality has allowed for the evolution of increased longevity in mammals
Proc. Natl. Acad. Sci. U.S.A.
Niche construction, biological evolution and cultural change
Behav. Brain Sci.
Cited by (102)
Sexual dimorphism in the cranium and endocast of the eastern lowland gorillas (Gorilla beringei graueri)
2023, Journal of Human EvolutionThe economics of brain size evolution in vertebrates
2022, Current BiologyExploring innovative problem-solving in African lions (Panthera leo) and snow leopards (Panthera uncia)
2022, Behavioural ProcessesNatural conditions and adaptive functions of problem-solving in the Carnivora
2022, Current Opinion in Behavioral SciencesCitation Excerpt :In wild narrow-striped mongooses (Mungotictis decemlineata), 63% of individuals with a demonstrator solved a puzzle box (Figure 2b) compared to only 25% of individuals without a demonstrator [58••]. While social learning has not been tested in solitary carnivores, brain size correlates with the length of time that juveniles associate with their mothers after weaning, a period of time where juveniles are presented with many social learning opportunities by their mothers [59,60]. These results generally support the Cultural Intelligence hypothesis and suggest that natural selection may have favored the use of social information during problem-solving by carnivores [13].
Performance of horned puffins (Fratercula corniculata) on an object permanence task
2020, Behavioural Processes