Scientists say it is important to foster digital literacy and healthy online habits in children who have grown up using social media. Credit: StockPlanets/E+/Getty
Growing evidence suggests that concerns about social media’s effects on children and adolescents go beyond a conventional moral panic. Researchers are examining how social platforms interact with the developing brain, attention, reward systems and sleep, while governments consider restricting young people’s access. The findings do not establish that social media alone causes harm, but they point to potential risks during a period of major biological and psychological development.
In 1972, sociologist and criminologist Stanley Cohen explored the concept of moral panic in his book Folk Devils and Moral Panics. The term describes the recurring tendency of societies to focus on emerging conditions, behaviours, identities or communities 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.
Although worries about digital and social media use by children and adolescents are now widespread, a growing body of scientific literature is investigating the nature and prevalence of possible harms, as well as ways to address them.1,2
Nature Spotlight: Neuroscience
One difference between this debate and a typical 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.”
Scientists are working to understand what might make adolescents particularly vulnerable. “We know that adolescence is a time of profound changes in the way the brain develops and responds to social, peer, and family conditions,” said psychologist and neuroscientist Eva Telzer, 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 developmental period, adolescents are also spending more time using digital technology, particularly social media.
Governments around the world are responding to concerns about social media’s effects on children and adolescents by attempting to regulate or restrict its use. In December last year, the Australian government implemented a social-media ban for people under 16, aimed at preventing them from accessing or holding accounts on platforms including Facebook, Instagram, TikTok and X. Several European countries, including the UK, France and Italy, are also considering similar measures.
These developments raise fundamental questions, Telzer said. “How might this social environment rewire the developing brain at this really critical time when the brain is so sensitive?”
A perfect storm during adolescence
From birth, a child’s brain grows rapidly in both size and connectivity. Neurons multiply and form connections known as synapses. During infancy, however, this growth is accompanied by synaptic pruning, in which some connections are severed and removed. By the end of the process, the number of synapses is approximately 40% lower than it was at the beginning. Neurons also die through a process called apoptosis. At the same time, the remaining neurons acquire a coating of insulating white matter called myelin, which is essential for efficiently transmitting electrical impulses.
During adolescence, different regions of the brain mature at different times. That sequence is not especially conducive to calm, rational thought and behaviour.
The earliest-maturing areas contain many 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,” said Mitch Prinstein, a psychologist at the University of North Carolina at Chapel Hill.
The prefrontal cortex, the brain region involved in decision-making, judgement and the processing of emotions such as fear and happiness, is among the last areas to mature.
This pattern may leave the adolescent brain particularly responsive to features built into social-media platforms, including comparison mechanisms such as likes and reward-oriented tools 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 said. “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.
Social media may therefore create what Prinstein calls a “perfect, tragic storm” for young people. “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 said.
Dopamine is an important part of the picture. The neurotransmitter is implicated in several addiction disorders, and the order in which brain regions mature makes adolescents especially sensitive and responsive to rewards. Social media supplies those rewards frequently: likes, new followers, positive comments and other interesting content can all produce a dopamine rush. 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 said.
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 direct rewards supplied by social media might condition adolescents to seek constant stimulation, making it more difficult to sustain 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 and found a linear relationship between social-media use and symptoms of inattention.4
Researchers have also used brain imaging to investigate possible changes associated with screen use. Nivins and his colleagues used magnetic resonance imaging to examine changes linked to social-media use, video-game play or television viewing over four years in 1,462 participants in the Adolescent Brain Cognitive Development Study.5 They found that children who used social media more frequently had a small but significant reduction in the volume of the cerebellum. This brain region is known for regulating movement and balance and also plays important roles in cognition, memory and communication.
“Why we’re concerned … the cerebellum is involved in all mental illnesses,” Dr Nibbins said, suggesting that the finding could be one mechanism linking heavy social-media use with anxiety and depression. The study identifies an association, not proof that social-media use directly causes these changes or conditions.
Developmental neuroscientist Samson Nibbins used imaging techniques to investigate how different types of screen use affect the developing brain. Credit: Senthil Kumar/Aswath Photo Studio
Sleep disruption associated with social-media use could also affect myelin, the insulating component of white matter that supports efficient nerve conduction and healthy brain function. Sleep deprivation can impair the formation and maintenance of myelin.
A study of 976 children in the Adolescent Behavioral and Cognitive Development Study found an association among shorter sleep duration, deterioration in white-matter tissue, screen time and depressive symptoms during early adolescence. The paper also suggested that sleep duration and its effects on white matter could mediate the relationship 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 said.
Source: www.nature.com
