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Are Humans Hard Wired For A Limited Social Circle

2010-03-09 12:54
Despite growing insight into neuroscience and the physical limitations of our consciousness, we have the tendency to ascribe a limitlessness to our minds. We readily accept the existence of certain boundaries in the material world, like fences, social stations, rules, laws (of physics and of states), or physical characteristics ( You must be this tall to ride the roller-coaster ), but when it comes to the inner world - the mind, our memories, our imagination, our cognition, and our social skills - we have trouble conceiving of real mechanical limits. When a word eludes us, playing about the periphery of our cognition ( tip of the tongue ), do we complain about faulty hardware When we forget that cute girl 8217;s name we just met at the party, do we blame the lack of available short-term memory data chunks It 8217;s only through neurological research that we 8217;re even aware of the bioelectric interplay that is our thought process; in general, in everyday existence, we donв t think of our thoughts and our emotions in cold, mechanistic terms. We simply think, remember, feel, etc., without getting all meta about it. Yet it 8217;s clear that there are physical limits to our minds. The consensus on short-term memory, for example, is that most people are limited to retaining just seven items at once, or seven chunks of data - a physical limitation, hard wired into our brains. What if we were similarly hard-wired to effectively manage a limited number of personal relationships It seems plausible. If memory has a corresponding physical capacity, why wouldnв t other functions of the brain Dunbarв s Number Primatologists have often noted that non-human primates live in grooming cliques, tight-knit social groups of varying sizes where grooming is the means by which the members socialize and stay tight-knit. The number of members in a non-human primate grooming clique arenв t randomized, but rather dependent on the size of the particular primateв s neocortex region of the brain. Greater volume is associated with a higher companion threshold. Primate species with bigger brains tend to have larger social groups. A British anthropologist named Robin Dunbar figured the same principle ought to apply to all primates - human and non-human alike. In 1992, using the predictive value of neocortex size, he was able to accurately predict average group size for thirty-six species of monkeys and apes. He then followed suit (abstract) for human primates and came up with a human maximum mean group size of 150 and an intimate circle size of 12. Hypothesis in hand, he then compared his prediction with observed human group sizes, paying special attention to the anthropological literature and reports from hunter-gatherer societies. The homo sapien brain developed around 250,000 years ago, so looking at hunter-gatherers was his best bet for approximating the social behaviors of Paleolithic ancestors. For the most part, his predictions held true. The upper limit for human so...
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