If you’ve been working in a professional capacity for 3-5 years, chances are you’ve come across at least 500 people. Shouldn’t you be connected to them?
Professionals are constantly reminded of the ubiquity and necessity of networking. Business bloggers chronicle the journey (1) to 5,000 LinkedIn connections, and sound the alarm at the danger (2) of maintaining fewer than 500. An ever-expanding arms race of online networking encourages professionals to adorn their profiles with corporate banalities (see: “investment ninja,” or “breaking synergy down to a science”) and pressures them to send connection requests to near-strangers in their industries.
Of course, network-expansion isn’t confined to professional arenas like LinkedIn. Social platforms are designed to foster similar patterns of extreme networking. Facebook and Instagram suggest accounts for their users to add as friends, while Twitter users’ feeds are often overrun by tweets from users they don’t follow. Our favorite networks are constantly nudging us to expand our circles of interaction. Scientifically speaking, just how big can our networks get?
According to anthropologist Rubin Dunbar, the answer is 150. Dunbar conducted a study in 1992 showing a correlation between neocortex volume and social group size in primates (3). His findings departed from the going theory — that big brains were most closely linked to complex ecological factors like extensive food-searching. (To be transparent, both theories still exist today, often in concert.) The next year, Dunbar published, “Co-evolution of Neocortex Size, Group Size and Language in Humans.” (4) With this paper, Dunbar explicitly linked his previous findings to humans, providing extensive historical evidence for limitations on human group size. More famously, this paper gave us the “Dunbar Number” of 150.
Along with sensory perception and motor skills, the neocortex (the brain region implicated in Dunbar’s analysis) is responsible for complex associative functions like inhibition, reasoning, and language. It’s not surprising, therefore, that a large neocortex leads to prolific social skills. What might be surprising is the converse: that evolutionarily speaking, the adaptive advantage of social skills led to larger neocortices. In his 1998 paper “The Social Brain Hypothesis,” Robin Dunbar broke with conventional wisdom once again, arguing that social behavior (not factual information processing) is the driving force behind humans’ evolutionary departure from our tree-swinging ancestors (5).
Compared to other species (even our close primate ancestors), humans are particularly well-endowed when it comes to the neocortex. But our Dunbar Number of 150 is still below the number of connections most of us have on social media, and well below LinkedIn’s holy grail of 500.
This poses the question: does technology allow us to cheat evolution? In some ways, yes. Modern medicine prolongs lives by decades. Tinder and Bumble expedite the search for sexual partners. But can social and professional networks help us cheat the evolutionary limits on group size?
According to a 2011 analysis of Twitter network activity (6), the answer is a resounding “no.” The study collected data from 1.7 million users over six months, in search of the maximum number of “stable relationships” (not the number of followers, but rather the number of users with whom regular interaction is sustained) for a typical Tweeter. The answer? 100 to 200 relationships — right in Dunbar’s wheelhouse.
If we forge connections online but cannot maintain those relationships according to the rules of evolution, we are then confronted with the frightening possibility that our social networks are actually antisocial behavior masquerading as hypersociality.
“So what?” you ask. Sure, you have more than 150 friends on Facebook. And yeah, you have more connections on LinkedIn than some anthropologist from the 90s says you should. It might get you a few more likes on your profile pic, or even land you an interview. What’s the harm in networking too much, which — according to Dunbar himself — is the reason we have bigger brains?
The dangers of over-networking stem from the dual explanation behind Dunbar’s group size research: social interactions are limited by both time and cognition.
How does time limit group size? We can’t have 5,000 intimate friends, simply because we wouldn’t have time to attend to them all. By adding more people to our “networks,” we’re spreading ourselves thin and giving ourselves less time to focus on what (or who) really matters. The same logic applies to professional networking, except instead of sacrificing the intimacy of your friendships, you sacrifice the average usefulness of your connections. (Let’s face it — that so-called “marketing hacker” who added you on LinkedIn from five states over is unlikely to offer you your dream job.)
The cognitive limits on network size draw on the evolutionary salience of social interactions. Our brains are wired to socialize. In many ways, they’re wired because of it. The engineers at Facebook and Twitter knew this before you or I did — they’ve been exploiting it for decades to optimize their networks (7) for our viewing pleasure (or, at least, obsession). They manipulate our fear of missing out and our insatiable desire to connect, giving us little bursts of dopamine with each new friend request or like-notification. You know the feeling, but you may not have realized how scientifically it was concocted.
If you’re thinking this constant cycle of craving and satisfaction sounds a lot like gambling or drug use, you’re on the right track. The relative novelty of networking via smartphones makes it difficult to draw long-term conclusions about the effects of networking addiction. However, the scientific community is in relative agreement that cell-phone usage, largely fueled by social networking, closely resembles other addictive behaviors. A 2016 review in Frontiers in Psychiatry (8) compiled information from 162 previous studies, many of which linked problematic usage of social media to depression and neuroticism. The review concluded that “there is a consensus about the existence of cell-phone addiction.” The next year, a study from Korea University in Seoul delved into the neural correlates of the epidemic. Researchers found that teenagers with diagnosed internet or smartphone addiction have abnormally high levels of GABA (the brain’s primary inhibitory neurotransmitter) in the anterior cingulate cortex (ACC), an area with connections to major executive and emotional neural networks (9, 10).