Perceptual Partitioning in Human History

Abstract

The social mechanisms of morality (mimicry, synchrony, and perceived identity overlap) are optimized in groupings of between 20 and 150 human beings. This optimization is due to the cortical size and density of the human brain. The human neocortex is responsible for the incredible symbolic processing that we experience each day, such as thinking, daydreaming, or talking about present, past, or future events. Recall that humans are also considerably more likely to entrain with those who are familiar, appear physically similar and who seem competent. This homophily bias and competence bias indicates that we prefer the presence of certain individuals over others, but it does not tell us whether or not there are limitations to the size (i.e., number) of individual interpersonal bonds that can be made.