Scientists are increasingly examining how social media affects children and adolescents, whose brains are still undergoing major developmental changes. Although concerns about technology can resemble the “moral panic” described by sociologist and criminologist Stanley Cohen in 1972, researchers say the issue warrants serious study: young people themselves report difficulties controlling their social-media use, while studies have linked heavier use with poorer attention, changes in brain structure, sleep disruption and depressive symptoms.
Scientists say it’s important to foster digital literacy and healthy online habits in children who have grown up using social media.Credit: StockPlanets/E+/Getty
In his 1972 book Folk Devils and Moral Panics, Stanley Cohen explored the idea of moral panic: societies periodically become fixated on emerging conditions, behaviours, identities or communities that are portrayed as threats to the public. Such episodes are often marked by public “hand-wringing”, calls for action from social leaders and media coverage in which experts diagnose the problem and propose solutions.
Concerns about the effects of digital and social media on children and adolescents might appear to fit that pattern. Politicians, religious leaders and others are increasingly warning that social media harms young people. At the same time, a growing body of scientific research is investigating the nature and prevalence of those harms, as well as possible responses.1,2
One important difference from a conventional moral panic is that young people themselves are expressing concern. “It’s not just older generations who are saying, ‘Kids, get off your screens,’” says Georgia Turner, a neuroscience researcher at the MRC Cognitive and Brain Sciences Unit at the University of Cambridge. Turner and her colleagues found that nearly half of adolescents consider themselves addicted to social media.
“Whether or not that’s the correct clinical terminology, we’re clearly dissatisfied with the use of screens,” Turner said. “I would say that we should treat people who believe they have a problem as if that in itself is a problem or a concern that we need to try to understand.”
Researchers are working to understand what makes adolescents particularly susceptible to problematic screen use. “We know that adolescence is a time of profound changes in the way the brain develops and responds to social, peer, and family conditions,” says Eva Telzer, a psychologist and neuroscientist who is co-director of the Winston National Center for Technology Applications, Brain, and Psychological Development at the University of North Carolina at Chapel Hill. During this critical stage, adolescents are also spending more time using digital technology, especially social media.
Governments around the world are responding with efforts to regulate or restrict social-media use by children and adolescents. In December last year, the Australian government implemented a social-media ban for people under 16, intended to prevent them from accessing or holding accounts on platforms including Facebook, Instagram, TikTok and X. Several European countries, including the United Kingdom, France and Italy, are also considering similar measures.
These developments raise fundamental questions, Telzer says. “How might this social environment rewire the developing brain at this really critical time when the brain is so sensitive?”
A perfect storm
From birth, the brain grows rapidly in size and connectivity as neurons multiply and form connections called synapses. During infancy, this growth is accompanied by synaptic pruning, in which some synapses are severed and removed. By the end of the process, the number of synapses is approximately 40% lower than at the beginning. Neurons also die through a process known as apoptosis. Meanwhile, the remaining neurons acquire an insulating coating called myelin, which forms part of the brain’s white matter and helps electrical impulses travel efficiently.
During adolescence, different brain regions mature at different times, and that sequence is not particularly favourable to calm, rational decision-making or behaviour.
The first regions to mature are rich in receptors for oxytocin, a hormone involved in social bonding, and dopamine, a neurotransmitter associated with reward and pleasure. “That’s why middle schoolers all want to talk about who sits where in the cafeteria and who’s more popular than who,” says Mitch Prinstein, a psychologist at the University of North Carolina at Chapel Hill.
The prefrontal cortex is among the last brain regions to develop. It is essential for decision-making, judgement and the processing of emotions such as fear and happiness.
This developmental sequence may leave the adolescent brain especially sensitive to features built into social-media platforms. These include comparison mechanisms such as likes, as well as potentially habit-forming features such as push notifications and infinite scrolling. “Imagine in the ’80s there was skywriting in your neighborhood where the most popular kid in school was now talking about you with most of the rest of the grade,” Prinstein says. “You’ll run down the street looking for them in your neighborhood. It’s impossible to resist.”
Neuroscience researcher Georgia Turner says young people may be more sensitive to the dopamine-driven rewards provided by social media.
That, Prinstein says, is what social media does to young people, creating a “perfect, tragic storm”. “The brain is hypersensitive to this, but it can’t be stopped because the brain’s brakes, the prefrontal cortex, aren’t fully developed until the mid-20s,” he says.
Dopamine is a major part of the concern. The neurotransmitter is involved in several forms of addiction, and because of the order in which brain regions mature, adolescents are particularly sensitive and responsive to rewards. Social media offers those rewards frequently: likes, new followers, positive comments and interesting content can all produce a dopamine rush, Turner says. Similar rewards occur in everyday life, but generally much less often.
That pattern could affect the developing brain. “For example, we now know that increased dopamine transmission can actually have profound effects on brain maturation, especially in younger age groups, and on cognitive control, inhibition, and reward sensitivity in adulthood,” Turner says.
Telzer and her colleagues studied 79 children and adolescents and found that those who spent more time on their smartphones during school hours—mostly using social media—performed worse on tests of concentration and attention control. The researchers suggested that the immediate rewards provided by social media might condition adolescents to expect constant stimulation, making it more difficult to sustain their focus.3
Another study, co-authored by developmental neuroscientist Samson Nibbins of the Karolinska Institute in Stockholm, followed more than 8,300 children for four years. It found a linear relationship between social-media use and symptoms of inattention.4
Researchers have also used brain imaging to investigate changes associated with social-media use. Nibbins and his colleagues analysed magnetic-resonance images collected over four years from 1,462 participants in the Adolescent Brain Cognitive Development Study. They compared associations with social-media use, video-game play and television viewing.5
The researchers found that children who used social media more frequently had a small but significant reduction in the volume of the cerebellum. This region is known for regulating movement and balance, but it also has important roles in cognition, memory and communication. “Why we’re concerned … the cerebellum is involved in all mental illnesses,” Nibbins said, suggesting that the finding could represent one mechanism linking heavy social-media use with anxiety and depression.
Developmental neuroscientist Samson Nibbins used imaging techniques to investigate how the use of different types of screens affects the developing brain.Credit: Senthil Kumar/Aswath Photo Studio
Social-media-related sleep disruption could also affect the formation of myelin, the insulating component of white matter that is important for efficient nerve conduction and healthy brain function. Sleep deprivation can impair myelin formation and maintenance.
A study of 976 children in the Adolescent Brain Cognitive Development Study found an association between shorter sleep duration, poorer white-matter tissue, screen time and depressive symptoms in early adolescence. The paper also suggested that sleep duration and its effects on white matter mediate the association between increased social-media use and increased depression-related symptoms.6 “Social media is the number one reason kids aren’t getting the recommended amount of sleep,” Prinstein says.
Source: www.nature.com