Neocortical development and social structure in primates

  title={Neocortical development and social structure in primates},
  author={Toshiyuki Sawaguchi and Hiroko Kudo},
The relationships between the relative size of the neocortex and differences in social structures were examined in prosimians and anthropoids. The relative size of the neocortex (RSN) of a given congeneric group in each superfamily of primates was measured based on the allometric relationships between neocortical volume and brain weight for each superfamily, to control phylogenetic affinity and the effects of brain size. In prosimians, “troop-making” congeneric groups (N=3) revealed a… 
It is suggested that language evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than is possible by direct observation alone.
The evolution of the social brain: anthropoid primates contrast with other vertebrates
It is suggested that, among vertebrates in general, pairbonding represents a qualitative shift from loose aggregations of individuals to complex negotiated relationships, and that these bonded relationships have been generalized to all social partners in only a few taxa (such as anthropoid primates).
Primate brain size is predicted by diet but not sociality
This work uses a much larger sample of primates, more recent phylogenies, and updated statistical techniques, to show that brain size is predicted by diet, rather than multiple measures of sociality, after controlling for body size and phylogeny.
Both social and ecological factors predict ungulate brain size
A simple index of sociality was a better predictor of both total brain and neocortex size than group size, which may indicate that the cognitive demands ofsociality depend on the nature of social relationships as well as the total number of individuals in a group.
Neocortex size predicts deception rate in primates
  • R. ByrneN. Corp
  • Biology, Psychology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2004
It is shown that the use of deception within the primates is well predicted by the neocortical volume, when observer effort is controlled for; by contrast, neither the size of the rest of the brain nor the group size exert significant effects.
Primate encephalization.
  • L. Lefebvre
  • Psychology, Biology
    Progress in brain research
  • 2012
Baboons (Papio anubis) living in larger social groups have bigger brains
Below is the unedited preprint (not a quotable final draft) of:
Group size is a function of relative neocortical volume in nonhuman primates. Extrapolation from this regression equation yields a predicted group size for modern humans very similar to that of
Neocortex size predicts group size in carnivores and some insectivores
Data for carnivores and insectivores are used to test the generality of this relationship and suggest that carnivores lie on the same grade as the primates, but that insectivore lie on a separate grade to the left of these two orders.
Encephalizations and Cerebral Developments in Genus Homo
Recent advances in the knowledge of intrinsic organization of cerebral cortex and in the patterns of genetic expression are able to better outline the trajectories as the metabolic and structural constraints of the qualitative and quantitative encephalic development.


The Relation between Ecology a Social Structure in Primates.
This article introduces a new category of social structure for the primates•the age-graded-male troop, and calls attention to the reproductive group as an organic unit that shows stages of growth and decline which may vary under different environmental circumstances.
Evolution of the Brain and Intelligence
The evidence of the actual evolution of the vertebrate brain is analyzed by reviewing morphological data on endocasts and skeletons of several hundred fossil species and comparing these with living
Studies on the evolution of multiple somatosensory representations in primates: The organization of anterior parietal cortex in the new world callitrichid, Saguinus
The organization of somatosensory cortex in the tamarin (Saguinus) is studied in hopes of better understanding differences in the organization of anterior parietal cortex in primates and how these differences relate to phylogeny.
Evolutionary Theories on Primate Social Structures and Behaviors: A Discussion on a Synthesis
Imanishi's primate sociology and Itani's theory can be fruitfully reconstructed in the framework of neo-Darwinism when the idea of “holism” is abundant, and the reconstruction would be fruitful to develop theories on evolutionary mechanisms of social structures and behaviors in primates.
New and revised data on volumes of brain structures in insectivores and primates.
More than 2,000 data on volumetric measurements of 42 structures in a variety of up to 76 species (28 insectivores, 21 prosimians, 27 simians) are given. All volumes measured in serial sections were
Primate brain evolution.
This is not an introduction to the subject; a reader lacking a background in basic neuroanatomy and some exposure to allometry will be swamped in short order and the generally excellent bibliographic references make the book a current point of departure for the serious student just getting into the field.
Quantitative Cytoarchitectonics of the Cerebral Cortices of Several Prosimian Species
The mass of modern axonal transport and electrophysiological studies clearly show by the coincidence of architectonic and functional entities that cytoarchitectonic studies can be a useful tool in working out the function of a brain structure.
The casts of fossil hominid brains.
The evidence suggests that, contrary to what is widely believed, the human brain was not among the last human organs to evolve but among the first.