Machiavellian intelligence hypothesis

In the book de Waal notes that chimpanzees performed certain social maneuvering behaviors that he thought of as being "Machiavellian".

[6][7] Byrne and Whiten edited two volumes that compiled interdisciplinary research exploring the theme, Machiavellian Intelligence: Social Expertise and the Evolution of Intellect in Monkeys, Apes, and Humans (Oxford University Press, 1988) and Machiavellian Intelligence II: Extensions and Evaluations (Cambridge University Press, 1997).

They observed that primates, particularly great apes, displayed intricate social behaviors such as alliance formation, deception, and reconciliation.

[8] Machiavellian intelligence may be demonstrated by primate behaviors including:[9] The claim that large brains are linked to large social groups in primates and cetaceans, on which the Machiavellian intelligence hypothesis is based, is criticized by a number of researchers for overlooking the availability of food as a common limiting factor for brain size and social group size.

These critics also cite that the "exceptions" in the form of small-brained primates in very large groups typically eat abundant but nutrient-poor foods (such as geladas that eat grass), as predicted by the food-based model, and argue that the higher individual need for nutrients put on by large brains causes groups to become smaller if the species have the same degree of digestive specialisation and environmental availability of food.