Brain

A great deal of research has been directed toward a better appreciation of how the brain operates when people engage in deception. Such research may be applied to the development of lie detection technology, but a thriving field of academic inquiry, the cognitive neuroscience of deception, has been making important progress in illuminating the processes by which deception is enacted at a neural level. This complex question has been addressed by a number of scientific disciplines, and convergent lines of research have included (but are by no means limited to) analysis of deceptive behavior in animals, developmental trajectories of deceptive behavior in children, loss of function and pathological studies of human adults, and more recently, psychophysiological and neuroimaging techniques.

Deception is a common feature of communication within human groups, but it is also a common feature of social interaction in nonhuman species. Reviews of deceptive behavior in animals illustrate a number of levels at which deception may be observed and that animals mislead, bluff, and deceive with a range of objectives and levels of sophistication or complexity.

By examining the brains of different species and the ways in which they live and breed together, a startling relationship is found between the average size of a social group and the size of the brain. Specifically, the bigger the social group, the bigger the brain. The “Machiavellian intelligence” or “social brain” hypothesis puts forward the idea that the comparatively large brains and complex cognitive abilities of humans have evolved as a result of intense social competition. It is suggested that earlier on in the human evolutionary lineage, some individuals may have developed increasingly sophisticated Machiavellian or manipulative and deceitful interaction strategies in order to obtain heightened social position and reproductive success, resulting in a developmental arms race.