Dunbar’s Number
Dunbar’s number is the supposed cognitive limit to the number of individuals with whom any one person can maintain stable social relationships.
This limit is a direct function of relative neocortex size, and that this in turn limits group size … On the periphery, the number 150.
This number was then compared with observable group sizes for humans.
Surveys of village and tribe sizes also appeared to approximate this predicted value, including 150 as the estimated size of a neolithic farming village; 150 as the splitting point of Hutterite settlements; 200 as the upper bound on the number of academics in a discipline’s sub-specialization; 150 as the basic unit size of professional armies in Roman antiquity and in modern times since the 16th century; and notions of appropriate company size.
