THE SOCIAL BRAIN

For generations, adolescence has been defined as a time of social connection—hanging out with friends, dating, and developing bonds outside the family. These interactions aren’t just cultural rites of passage; they help shape how young brains learn to navigate emotions, relationships, and risk.

But that social landscape is changing. In recent years, teens have been spending less time together in person. Daily face-to-face interactions with friends among children decreased from 53 percent in 2006 to 36 percent in 2022. While some alone time is normal and even “healthy,” experts warn that too much of it may impact key aspects of teen brain development, with consequences that can extend into adulthood.

How the “social brain” takes shape during adolescence. Adolescence, the developmental period that begins with puberty and, in terms of brain maturation, can extend into the early thirties, is a time of profound physiological, biological, and psychological change. At the brain level, our teenage years are a time of rewiring. Starting in puberty, the brain builds new connections to allow faster, more efficient exchange of information between distant areas of the brain. This reconfiguration enables the development of new skills, including emotion regulation and risk and reward evaluation.

Some of the most pronounced changes occur within a network of brain regions that scientists call “the social brain,” which is physically located in areas such as the medial prefrontal cortex, the anterior cingulate cortex, and the amygdala. The ‘social brain’ functions as a network that permits taking the perspective of others, interpreting the emotional expressions of our friends, and seeking out opportunities to bond. It’s why adolescents are experts at making new friends, energized by causes they are passionate about, and adept at the forefront of new ideas.

Although development of the social brain begins in puberty, it requires some socialization to mature fully. It’s a little bit like learning a language. Our brains are framed to learn how to speak a language, but we become experts in a particular language because of the input we receive early in life. In the same way, teens need some social interaction to fine-tune the neural systems that support social understanding and behavior.

As data indicate that teens, on average, experience less social connection than in previous generations, more scientists are trying to understand how this reduced socialization may impact brain development.

What scientists know—and don’t—about isolation and the teenage brain. Much of what scientists currently know about social isolation and the brain comes from two main sources: behavioral studies of adolescent humans and brain imaging studies in adolescent animals, such as mice.

At the behavioral level, most studies find that social isolation is associated with adverse outcomes like increased anxiety and greater vulnerability to addiction. In animal studies, researchers have found that isolation is associated with changes in the prefrontal cortex, an area involved in higher- and social cognition..

Part of this lack of human data stems from the current pace of social change. To understand how reduced social interaction affects brain development, scientists rely on longitudinal studies that follow large groups of children over many years. Only recently has such data begun to emerge, largely through the Adolescent Brain Cognitive Development (ABCD) Study, the largest long-term study of teen brain development in the United States. Launched in 2016, the ABCD Study followed the development of nearly 12,000 teens across the U.S., tracking both biological data, such as brain scans, and behavioral information, such as socialization patterns or screen time.“The ABCD data is finally allowing researchers to explore the relationship between kids’ behaviors and brain development more fully.

Using advanced computational tools that can analyze brain networks through structural and functional MRI data from nearly 3,000 pre-teens aged 11 to 12, a time when social interaction outside the household becomes more prominent than in childhood. The researchers relied on parents’ reports of children’s social behavior. Parents were asked to report on how often their child preferred solitude versus socialization and whether they acted ‘withdrawn,’ as in ‘not getting involved with others, Brain structure and the strength of brain circuits in teens who prefer solitude or were socially withdrawn differed from those who socialize more.

For example, the superior temporal gyrus, an area involved in social cognition, including the perception of motion, facial movements, and the understanding of other people’s mental states, was structurally and organizationally different in teens who had less frequent social interaction. The anterior cingulate cortex, an area that supports emotional processing, was also less developed in kids who socialized less.
Brain areas and networks associated with non-social skills were also affected. Areas involved in attention and decision-making, such as the dorsal attention network and the parahippocampal gyrus, were less integrated with other brain structures in kids who experienced higher levels of isolation. This was not expected that isolation would affect such an extensive array of brain networks,

Because adolescence is a period of heightened neural plasticity, changes that occur during this window may have more lasting effects. If not corrected, they can lead to the development of mental health issues like anxiety and depression that can last into adulthood.

When isolation is a concern—and when it isn’t. But heightened sensitivity does not mean inevitability. Adolescence is a time of heightened neuroplasticity, meaning that early interventions, such as offering children more opportunities to socialize or, in some cases, seeking help from a therapist, are likely to offset the negative impacts that excessive isolation can have on the developing brain.

Of course, not all types of isolation are problematic, Learn the difference between ‘normal’ preference for solitude and too much isolation, but that difference can sometimes be hard to gauge. Each person has a different need for socialization, Some kids want a big diverse group while others get their social input in smaller groups or in different kinds of settings, and that’s OK too. What matters most, is that adolescents have some form of meaningful interaction with peers.

Any response to social isolation should also account for individual differences. The success of ‘reversing’ negative impacts depends on the nature of the social isolation, the individual’s developmental history, and current context, Greater engagement in social interactions, establishing meaningful relationships, and genuine support from others can help mitigate any negative impacts of social isolation.”

Whether virtual interaction can provide similar benefits remains an open question. “A lot of kids’ social life takes place online, even for people who see each other in real life, they also interact virtually, so it’s becoming almost an extension of social life in a different realm. Just how much of this virtual hanging out can reap the same benefits of in-person connection is one of the questions to understand what kinds of virtual interactions are beneficial and which kinds are not. Maybe we can teach young people how to use virtual interactions better.