The impact of smart phones on the brain by age

May 8, 2024

Photo: StockCake

Increasingly, research is revealing the impact of devices on the brains of infants, children and adolescents. We’ve broken down the effects by age group, allowing you to understand both the developmental milestones and the neurological changes influenced by technological access.

Babies to Three

The first three years of life are a critical period for the human brain’s development. While brain development continues until age 25, with the frontal lobes—responsible for impulse control and planning—being the last to mature, the most pivotal time for brain development is from birth to age three.

A study conducted in 2023 suggests that excessive screen time during infancy may lead to changes in brain activity and issues with executive functioning (the ability to stay focused and control impulses, behaviours, and emotions) in primary school.

Before age five, the brain is rapidly fine-tuning and creating synapses and children’s brains are forming essential connections that will support higher-level abilities later in life. Both experiences and the environment play a crucial role in this developmental process, emphasising the importance of providing enriching and interactive activities to support optimal brain growth. These findings highlight the importance of monitoring and limiting screen exposure during these early years.

Dr. Wilkinson, a developmental behavioural paediatrician at Boston Children’s Hospital and a contributor to the study, recommends that if parents need to briefly use screens, they should incorporate interactive elements to enhance brain development. This approach adds layers of learning and can make screen time more beneficial.

The guidelines for this age are:

Keep children away from screens until they are 18 months old and limit digital media use to one hour per day for two to five year olds.
Until 18 months of age limit screen use to video chatting along with an adult (eg, family member).
Between 18 and 24 months screen time should be limited to watching educational programming with a caregiver.
For children 2-3, limit non-educational screen time to about 1 hour per weekday and 3 hours on the weekend days.

Ages Four to Six

A very important part of growing up is the ability to interact and socialise with others so creative play is vitally important for this age group. They still rely heavily on parents as role models and play should be live and immersive. Giving children devices at a young age deprives them of the chance to develop social skills through face-to-face interactions as they need to build empathy and interpret facial expressions.

Constant overstimulation from smartphone screens can be harmful to their brains, making them dependent on easy dopamine hits.

The guidelines for this age are:

Keep technology out of bedrooms.
Talk about what you watch together and how it applies to the world.
Limit screen time to 1 hour a day of high-quality programs and use free time for other more productive activities.

Ages Seven to 11

Between the ages of 7-11, children’s brains undergo significant neurological changes that are crucial for their cognitive, social, and emotional development. This period, often referred to as middle childhood, is marked by substantial growth in the prefrontal cortex, which is responsible for executive functions such as decision-making, problem-solving, and impulse control. Additionally, there is increased myelination, the process by which nerve fibers are coated with a fatty sheath called myelin, which enhances the speed and efficiency of neural communication. This leads to improvements in processing speed, attention, and working memory.

The upper end of this age range is where parents start to feel obliged to or forced by their children to get them a phone to keep in touch with them or from peer pressure to be like their friends. According to the Ofcom Children and Parents: Media Use and Attitudes Report 2020-2021, 49% of 8-11 year olds in the UK have their own smart phone.

Technology, particularly digital devices and online media, can significantly influence this stage of brain development. On one hand, educational apps and games can promote cognitive skills such as logical reasoning, spatial awareness, and language development. Interactive and well-designed educational content can engage children in ways that traditional methods may not, potentially enhancing learning outcomes. However, excessive use of technology poses several risks. Prolonged screen time can lead to reduced physical activity, which is essential for overall health and brain development. Moreover, the fast-paced and highly stimulating nature of many digital platforms can contribute to shorter attention spans and difficulties in sustaining focus on less stimulating tasks, such as homework or reading.

Social media (either with or without parental consent) and online interactions also play a growing role in children’s lives during these years. While these platforms can provide opportunities for social connection and communication, they also present challenges. Exposure to social media and cyberbullying and the over-reliance on peer validation on social media is a danger and can have a negative impact on their development if children are not equipped with the emotional resilience and coping strategies to navigate these experiences.

Additionally, the constant access to digital devices can interfere with sleep patterns, as the blue light emitted by screens can disrupt the production of melatonin, a hormone that regulates sleep. Poor sleep can adversely affect mood, cognitive performance, and overall well-being.

Children are becoming more and more independent of their parents and engaging in lots of activities during and after school. They still need plenty of exercise and playtime for healthy and strong brain and physical development, so it’s important to continue to limit time in front of the TV or computer screen.

The guidelines for this age:

Time watching television, playing video games and playing on the computer should be limited to one to two hours per day.

Ages 12 to 14

Between the ages of 12-14, children’s brains undergo significant neurological changes as they transition from childhood into early adolescence. Whilst the brain of a 12-year old has stopped growing in size it doesn’t mean that it’s not still developing.

This period is marked by extensive growth and restructuring in the brain, particularly in the prefrontal cortex and the limbic system. The prefrontal cortex, responsible for executive functions such as planning, decision-making, and impulse control, is still maturing. Meanwhile, the limbic system, which governs emotions and rewards, becomes more active. This developmental asynchrony often leads to heightened emotional responses and a propensity for risk-taking behaviours, as the emotional centres of the brain are more developed than the regulatory prefrontal cortex. This is why children of this age may still engage in potentially impulse behaviour.

Technology, especially social media, gaming, and digital devices, can have profound effects on the developing brains of 12-14 year olds. Social media platforms can amplify the already heightened emotional sensitivity of adolescents by providing constant opportunities for social comparison and peer feedback. The instant gratification from likes, comments, and shares can create a dependency on social validation, potentially leading to anxiety, depression, and issues with self-esteem. Additionally, the curated nature of online personas can foster unrealistic expectations and feelings of inadequacy among peers.

Gaming and extensive screen time also impact cognitive and social development. The immersive and often fast-paced nature of many digital games can affect attention spans, making it difficult for adolescents to engage in sustained focus required for academic tasks. Multitasking, common in digital environments, can impair the ability to concentrate deeply on single activities. Moreover, the competitive and sometimes aggressive nature of certain games can influence behaviour, potentially normalising aggressive responses and reducing empathy.

Furthermore, the pervasive use of digital devices can disrupt sleep patterns, crucial for brain development. The blue light emitted by screens interferes with melatonin production, leading to delayed sleep onset and reduced sleep quality. Adequate sleep is essential for memory consolidation, emotional regulation, and overall cognitive functioning. Chronic sleep deprivation can exacerbate mood disorders, reduce academic performance, and negatively impact physical health.

The neurological development of children between the ages of 12-14 is a complex and critical process influenced by various factors, including technology use. This is also the time when many children on entering senior school start to carry around a smartphone (ie. super computer) in their pockets and the risks of this need to be managed very carefully.

Choosing to wait until high school or even 16 is a subject being talked about more and more often when it comes to teens and smartphones. It doesn’t mean denying them a simple phone on which to connect and communicate but seriously restricts/omits the harmful aspects of having full access to the outside world.

While digital media can offer educational benefits and social connectivity, its impact on emotional well-being, cognitive development, and sleep requires careful management. Balancing screen time with offline activities, setting healthy boundaries, and promoting digital literacy are essential strategies to support the positive development of adolescents during this transformative period.

Ages 14 to 18

Between the ages of 14-18, adolescents undergo profound neurological development, particularly in the prefrontal cortex and the limbic system. The prefrontal cortex, which is responsible for executive functions such as planning, decision-making and impulse control, continues to maturity. This maturation process enhances adolescents’ abilities to think critically, make informed decisions and control their impulses. Simultaneously, the limbic system, which governs emotions and reward processing, remains highly active. This can lead to heightened emotional responses and a strong drive for novel and rewarding experiences.

Technology, particularly social media, gaming, and digital devices, significantly influences this developmental stage. Social media platforms can impact the brain’s reward system by providing constant streams of social validation through likes, comments, and shares. This can create a dependency on external validation, potentially affecting self-esteem and contributing to anxiety and depression. Adolescents may also engage in social comparison where they measure their self-worth against the often idealised portrayals of peers’ lives, leading to feelings of inadequacy and lower self-esteem.

Gaming and extensive screen time can also affect cognitive and emotional development. While some video games can enhance problem-solving skills, strategic thinking, and spatial awareness, excessive gaming can lead to negative outcomes. The immersive nature of many games can promote prolonged screen time intefering with other important activities such as physical exercise, face-to-face social interactions and academic responsibilities. The fast-paced and often overstimulating nature of digital media can contribute to shorter attention spans and difficulty in sustaining focus on less stimulating tasks, impacting academic performance and real-life task management.

Most young adults in the latter range of this age group are ready to own a smartphone however, high schoolers are still unpredictable and giving them unsupervised internet access can be a detriment to their development and that of their peers. It is important to model and teach them good smartphone habits setting times when there is no screen time, such as during dinner or bedtime to ensure children are getting enough sleep.

Many tech giants have been known to take a cautious approach when it comes to giving their own children smartphones, often delaying access until they are older. Here are some notable examples:

Steve Jobs (Apple Co-founder):
- Steve Jobs was known for limiting his children’s use of technology. According to biographer Walter Isaacson, Jobs didn’t let his kids use the newly released iPad in 2010, and he imposed strict rules on their technology usage at home.
Bill Gates (Microsoft Co-founder):
- Bill Gates revealed in interviews that he and his wife Melinda set a minimum age of 14 for their children to get smartphones. They also implemented screen time limits and banned phone use at the dinner table.
Sundar Pichai (CEO of Alphabet Inc. and Google):
- Sundar Pichai has spoken about limiting his children’s screen time. He mentioned in a 2018 interview with The New York Times that his 11-year-old son didn’t have a phone yet.
Tim Cook (CEO of Apple):
- Tim Cook has expressed concern about children overusing technology. He has mentioned that he does not want his nephew to use social media and limits his own screen time.
Evan Williams (Co-founder of Twitter):
- Evan Williams and his wife decided to limit their children’s exposure to screens. They emphasised a technology-light household, providing them with plenty of books and encouraging other activities instead of screen time.
James Steyer (Founder of Common Sense Media):
- James Steyer said in an interview with the New York Times that he would wait until his kids are in high school before handing them a smartphone.

These examples highlight a common trend among tech leaders: they tend to be more restrictive about their children’s use of technology, particularly smartphones, compared to the general population. This cautious approach often includes setting age limits, enforcing screen time restrictions, and encouraging alternative activities.

Is it purely about timing?

A report conducted by Stanford Medicine from 2021 concluded that it’s not the timing of giving a mobile device to a child that matters. It’s what the child is doing with the device supported by the parent continuing to make the decisions about their technology use.

Therefore, while most adolescents are ready for supervised smartphone use, some might still be lagging behind in terms of the level of maturity. To evaluate your child’s readiness, ask yourself the following questions:

Is your child asking for a smartphone for safety reasons or purely social ones?
Is your child ready to have limitations put on apps downloaded?
Is your child mature enough to use the photo, video, and text functions responsibly, not to text during class, or disturb others with conversations?