is extraordinary. It illustrates something scientists have known for years: flesh-and-blood friendships take work. And that’s because social interactions take work. And by work, I mean in a biochemical, energy-expending kind of way. Some researchers believe social interactions are the most complex, energy-intensive jobs your brain can consciously perform. Every time it intermingles at a cocktail party or consoles a friend, the organ experiences the cognitive equivalent of an aerobic workout.
Says Chelsea Wald, writing in Nature magazine: “[Researchers] suspect that the cognitively demanding act of socializing can actually build up the brain—like exercising builds up muscles. This ‘brain reserve’ may then act as a buffer against functional loss, even in the face of conditions such as Alzheimer’s disease.”
Suppose you were the scientist hypothesizing that social interactions are cognitive calisthenics. You might predict that the more social interactions you have, the more you exercise the brain regions responsible for those interactions. You might further hypothesize that the neural tissue will become bigger and stronger or more active as a result. You might guess there would even be bleed-through effects, given that the job descriptions of most brain regions are hopelessly intertwined with those of other regions, all moonlighting to produce a broad array of functions. From cell to behavior, you can measure whether growth is occurring.
And scientists have. Though the data are largely correlative, growth is exactly what they find.
Let me pause for a moment to define a few terms: social activities, social networks, and social cognitions. Researchers define these terms much as the public does, especially if that public uses words like “neurological substrates.” Social activities are the actual experiences you have with others, whether going out on a boat or going out on a date. Social networks are the number of people with whom you willingly have those experiences. Close friends and family generally populate these activities. Social cognitions are the psychological (and by implication, neurological) substrates you use to interact with others when socializing.
On to the studies showing that the brain is being exercised.
The more social relationships you maintain, the bigger the gray matter volume in specific regions of your frontal lobe. Which means that relationships are to the frontal lobe what milk shakes are to your waistline. The frontal lobe is the large region right behind your eyes, running to the middle of your head (where a headband would sit). This region is associated with a cognitive gadget called mentalizing, or Theory of Mind. Mentalizing is the ability to discern the mental states of others, particularly their motivations and intentions. It’s as close to mind reading as your brain will ever get. Mentalizing abilities play a powerful role in establishing and maintaining social relationships, as you can imagine.
The frontal lobe is also responsible for helping you predict the consequences of your own actions. It helps you suppress socially inappropriate behaviors and even make comparative decisions. For many reasons, these are important regions to keep fat and happy.
The amygdala, a little almond-shaped nodule dangling just behind each ear, is involved in processing your emotions. It too is affected by levels of social activity. The higher the overall number of (and the greater the variability in) the types of relationships you maintain, the bigger your amygdala becomes. These aren’t small changes. If you triple the number of people in your social network, you double the volume of your amygdala. Wondering how you’d keep up with all those people? While you maintain your closest relationships with five people at a time, researchers find, you can have meaningful relationships of varying quality with an additional 150 people. Think of it as rings of relationships.
Social activity also affects a region called the entorhinal cortex, which helps you recall important things like your first kiss. This romantic bundle of nerves, which also helps process other types of memories (and many types of social perceptions), is located in the temporal lobe, the brain regions closest to your eardrums.
Given the rise of the Internet, does it matter which kind of social network is being measured, silicon- or carbon-based? It does. For example, gray matter changes in non-amygdalar regions (like the frontal lobe and entorhinal cortex) occur only with flesh-and-blood interactions. In contrast, density changes in the amygdala are specifically associated with the size of both Web-based social networks and the number of face-to-face social interactions. The reasons for these differences, extraordinary as they may sound, are not known.
Not all social interactions are created equal, however. You don’t have to look any further than a typical day in an American office, populated by dysfunctional management, for an example.
The boss from hell
The boss wore his unpleasantness like a purity ring on his middle finger. He publicly announced the contents of private meetings to his entire forty-person staff. He slapped the hand of a loyal employee who had worked for the company for forty-four years. When that employee asked for time off to go to the hospital where her daughter had suddenly been admitted, the boss replied, “What are you going to do, hold her hand?”
I describe this narrative, one of many stories online chronicling chronically bad working relationships, to counter an impression you might be getting from this chapter: that every relationship provides neurological benefit. The truth is just the opposite. You can have many relationships with people, but if they’re negative, they’re unhealthy. Studies show that it’s not the overall number of interactions that benefit health, but the net quality of the individual interactions. According to researchers from the University of North Carolina at Chapel Hill: “Social support and strain, which measured qualitative characteristics of social connections that are distinct from relationship quantity, mattered more for physical health in mid-adulthood, and continued to have impacts in late adulthood.”
Behavioral labs are coming up with all kinds of dos and don’ts for relationships. Interactions burdened with competitive one-upmanship provide no cognitive benefit at all. Relationships with people who are emotionally controlling, meddlesome, or consistently verbally aggressive (like that aforementioned boss) are worth limiting, if not ending altogether.
Drop the ego
What’s the secret to a good interaction for your brain? It’s a willingness to consistently take the other person’s point of view, actively seeking to understand a different perspective. You may agree with the other person or you may not, but the effort transforms casual conversation into meaningful brain food. If that sounds like Theory of Mind stuff we’ve been talking about, you are right on the research money. It’s also a scientifically nice way of saying: stop being so self-centered. This advice, by the way, is just as healthy for people much younger than your average Social Security recipient. Regularly engage people, and your brain will thank you at any age.
You can create an environment conducive to quality relationships. Social psychologist Rebecca Adams summarized how in a New York Times interview a few years back, if you cultivate the following:
• “repeated, unplanned interactions,” spontaneously rubbing shoulders with good friends
• “proximity,” living close by to friends and family members so those shoulders are available for rubbing
• “a setting that encourages people to let their guard down”
Not surprisingly, Adams relates, most of our tightest friendships initially form in college, where these conditions are met by design.
It’s best to have friends of all ages—including kids. That notion may transcend our culture’s perspective, but not our culture’s data. The more intergenerational relationships older people form, the higher the brain benefit turns out to be,
