Are Humans Hard Wired For A Limited Social Circle?

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’s name we just met at the party, do we blame the lack of available short-term memory data “chunks”? It’s only through neurological research that we’re even “aware” of the bioelectric interplay that is our thought process; in general, in everyday existence, we don’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’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 wouldn’t other functions of the brain?

Dunbar’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 aren’t randomized, but rather dependent on the size of the particular primate’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 social cohesiveness was groups of about 150, and this tended to occur in situations involving intense environmental or economic pressure – like war (Roman maniples contained around 160 men) or early agriculture (Neolithic farming villages ran about 150 deep, and 150 members marked the point at which Hutterite settlements typically split apart). Any higher, and it’d be too costly and require too much social “grooming” to maintain the group.

The hunter-gatherer existence self-regulates tribal size, really. Too few members make hunting unfeasible (as fit as he was, Grok wasn’t taking down a buffalo by himself, let alone lugging it back to camp), and foraging becomes more effective the more hands you commit to the task. A HG group had to be mobile and lean, able to follow the game when it moved. It had to be socially cohesive; people had to coordinate hunts, forage outings, and divvy up food. A large, ranging, sloppy group would mean more weak links, and in a social framework where every member was integral to the success of the whole, it simply wouldn’t work out. As we see with the Hutterites, a hunter-gatherer tribe that got too big for its britches would simply become two hunter-gatherer tribes rather than languish and fail.

(Overstepping Dunbar’s number might also increase stress. We clearly see that in farm animals. Increasing group size past optimal levels increases damaging behavior indicative of stress: feather pecking in hens and tail biting in pigs. No, we are neither pigs nor chickens, but we’re still sensitive to our environments.)

Okay, so there appears to be a limit to the number of people with whom a single person can maintain stable, rewarding relationships based on the size of the neocortex. This isn’t a time constraint thing here. If Dunbar is right, it’s an actual self-limiting brain mechanism forged 250,000 years ago that persists today. Agriculture no doubt pushed the limits by forcing us into crowded villages, but it’s only recently that our social networks have undergone another, even more drastic shift in size and composition: social media.

Facebook, Twitter, even regular old email are all forcing us into novel areas of social networking. We aren’t living in villages or tribes or bands. We’re running into childhood friends from thirty years ago. We’re getting text messages from twenty different acquaintances on a single day. Are we equipped to handle this sort of thing? Are we negatively impacting the quality of our social interactions? Are we spreading ourselves too thin? (See Dunbar’s take here.) Or does the new media allow us to transcend, or tinker with, previously immutable biological limitations? Maybe. I’m reminded of how working memory (a theoretical concept that’s beginning to replace short-term memory in some circles, working memory describes the temporary storage of information for immediate cognitive tasks like learning, reasoning, and calculating). As with short-term memory, most people are limited to seven or so “chunks” of working memory data. A chunk might be a single digit, a single word, or even a concept, but a few people can use advanced encoding techniques to expand the scope of each chunk. Where one person might be able to repeat seven digits from normal working memory, another might encode each chunk to include sequences of four or five numbers. This allows them to remember seventy numbers instead of seven, and they’re using the same brain stuff as everyone else. The neurological bandwidth hasn’t increased – their brains don’t physically grow larger – but they utilize the available bandwidth with greater efficiency.

Maybe Facebook and other social media offer the chance to make greater use of the available “socializing chunks” in our brain. Like with working memory, the seven chunks of available bandwidth are always going to be there, but it’s what you put inside that matters. Perhaps tools like Facebook allow us to “store” information on friends and family without taking up valuable mental real estate. I don’t think that’s “good” or “bad.” Hell, the reason we developed the written word was to avoid having to remember minutiae.

Maybe we still adhere to Dunbar’s number without really paying attention. I mean, it’s easy to tally Facebook friends into the thousands without actually knowing them. Adding a friend is almost an afterthought; is it really harmful, stressful, or contrary to our evolutionary social framework if we add an old acquaintance to our friend list and then never speak to them?

Problems arise, I think, when the virtual social network displaces the tangible one. Chatting online or through email is different than face-to-face interaction. Everything is calm and measured. There’s little room for incidentals, mistakes, or awkward pauses. You lose the physical contact and the body language cues. Emoticons can never replace emotive expression. As long as we maintain physical contact with friends, family, and loved ones, using online or virtual tools to augment the “real” relationships can only be helpful. Last week, for example, I met up with Brent Pottenger and Aaron Blaisdell, two regular commenters, in person. We established an online relationship, which has transitioned into an “actual” real world social network. PrimalCon is another great example. Without MDA there wouldn’t be a PrimalCon to bring this virtual community together in person. The Primal Blueprint is all about merging evolutionary truths with modern technology; it’s about cherry picking the best stuff from past and present.

Social media allows us to overstep our neurological social sphere boundaries. When it comes to diet, sunlight, sleep, stress, and physical exertion, I think we agree that sticking to ancestral, evolutionary precedent is the best policy, but that doesn’t have to apply to social networks. I guess I’m cautiously optimistic about the use of “social supplements” like Facebook or email. Overstepping our natural bounds is essentially what makes us human, after all. We just have to be smart about it.

I’d love to hear your thoughts. Hit me up with a comment and thanks for reading!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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