Machiavellian intelligence hypothesis

In primatology, the Machiavellian intelligence or social brain hypothesis describes the capacity of primates to manuever in complex social groups.^[1][2] The first introduction of this concept came from Frans de Waal's book Chimpanzee Politics (1982). In the book de Waal notes that chimpanzees performed certain social maneuvering behaviors that he thought of as being "Machiavellian".^[3]

This hypothesis posits that large brains and distinctive cognitive abilities of primates have evolved via intense social competition in which social competitors developed increasingly sophisticated strategies as a means to achieve higher social and reproductive success.^[4]

The term "Machiavellian intelligence" originates from the primatologist Franz de Waal, who noted that the behaviors of primates was so elaborate that it could perhaps be compared to political behavior today.^[5]

Primatologists Nicholas Humphrey, Andrew Whiten and Richard Byrne were instrumental in developing this theory.^[6][7] They observed that primates, particularly great apes, displayed intricate social behaviors such as alliance formation, deception, and reconciliation. These behaviors seemed to require cognitive abilities beyond what was necessary for basic survival tasks like foraging or avoiding predators.

As a concept, it is also conflated with, and mistaken for the Machiavellianism personality construct, which focuses on the affective-interpersonal traits of human beings, such as unemotionality and exploitativeness, while Machiavellian Intelligence deals with the social behaviors of primates and is not focused on immoral actions.^[8]

Machiavellian intelligence may be demonstrated by primate behaviors including:^[9]

• Mate seeking
• Acts of reciprocity and aggression
• Complex group manuevers, such as co-operation and competition^[10]
• Acts of misdirection by the primate

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.^{[citation needed]} Among primates as well as cetaceans, there are some opportunistic species that eat most types of food and other species that are specialised in particular types of food, as well as differences in the overall availability of food between different geographical regions in which the animals live. Some critics of Machiavellian intelligence argue that species that have to keep their use of nutrients down due to food poverty or specialisation in a rare type of food lowers average brain size for species that live in smaller groups, making big brains falsely appear to be linked to large groups due to the common causes of opportunistic foraging for nutritious food and a rich supply of food. 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.^[11][12]

• Dunbar's number
• Primate evolution
• Intelligence

• Byrne, R. W., & Whiten, A. (1988). Machiavellian intelligence. Oxford: Oxford University Press
• Carlson, N.R., et al. (2007). Psychology: The Science of Behaviour - 4th Canadian ed.. Toronto, ON: Neil R. Carlson.
• Humphrey, N. K. (1976). The social function of the intellect. In P. P. G. Bateson & R. A. Hinde (eds.). Growing points in ethology. Cambridge: Cambridge University Press
• Maestripieri, Dario. (2007) Macachiavellian Intelligence: How Rhesus Macaques and Humans Have Conquered the World. Chicago and London: University of Chicago Press