Screen time refers to the amount of time spent using an electronic device with a display screen such as a smartphone, computer, television, video game console, or tablet.
This activity can be either for educational, work, or entertainment purposes, but is most often a sedentary one, resulting in low physical activity.
Screen time is correlated with mental and physical harm in child development.
Too much screen time can lead to several negative outcomes, including: Sleep problems Increased risk of attention, anxiety, and depressive issues Higher risk of obesity Lower physical activity Possible delays in language and social-emotional development in young children
The positive or negative health effects of screen time on a particular individual are influenced by levels and content of exposure.
Screens are now an essential part of entertainment, advertising, and information technologies.
Smartphones have become ubiquitous in daily life.
In 2023, 85% of American adults reported owning a smartphone.
All forms of screens are frequently used by children and teens.
Data of children and teens in the United States show that the daily average of screen time increases with age.
TV and video games were once largest contributors to children’s screen time, but the past decade has seen a shift towards smart phones and tablets.
Typical Daily Usage Average screen times (U.S. data): 2-4 2 hours per week 5-8 2 hours per week Children 8–12: 4–6 hours/day Teenagers: up to 9 hours/day Adult averages continue to rise, especially with increased smartphone use
Race and socioeconomic class are associated with overall screen time.
Younger demographics and individuals who self-identified as Black and associated with above average screen use.
Additionally, Black and Latino Americans had longer screen times because of less access to desktop computers, which thus leads to more time on phones.
In children, the divide is much larger.
The discrepancy in the amount of screen time can also be attributed to a difference in income. In more affluent private schools, there has been a larger push to remove screens from education in order to limit the negative impacts that have been found from screen time.
However, in public schools there is more push for the use of technology with some public schools advertising free iPads and laptops to students.
Additionally, affluent families are able to afford nannies and extracurriculars that can limit the need for entertainment from screens.
The COVID-19 pandemic in 2020 increased screen time as people stayed indoors.
More screen-time has been linked with shorter sleep duration, decreased sleep efficiency, and longer sleep onset delay.
When using any screen before bedtime, the blue light emitted disrupts the body’s natural melatonin hormone production: Melatonin is produced by the brain’s pineal gland and controls the body’s internal clock.
The body’s circadian rhythm and it naturally is responsive to light.
Melatonin levels increase as the sun sets and remain at that increased state for the remainder of the night.
As the sun rises, melatonin levels start to drop.
Melatonin hormone reduction is what helps the body’s natural rhythm wake up due to the bursts of natural sunlight.
The light screens emit are in a similar spectrum of sunlight, but the blue light emission is what human circadian rhythms are most sensitive to.
Studies have shown that the blue wavelengths are closely correlated to those from sunlight, which is what helps the body keep in sync with the sunrise and sunset.
Using any screen prior to bedtime disrupts the body’s production of natural bedtime hormones which can trick the brain to believe it is still daytime making it harder to fall asleep.
Increased use of screens in children has also been shown to have an association with adverse effects on the quality of sleep in children.
The use of electronic media by children and adolescents does have a negative impact on their sleep,associating excessive media use with shorter sleep duration and delayed bed times.
Bedtime access and use of media devices is significantly associated with inadequate sleep quantity; poor sleep quality; and excessive daytime sleepiness.
Much of the time spent on screens for children is at night, which can cause them to go to sleep later in addition to the blue light from the screens making it more difficult to sleep.
Night-time use of screens is common for Americans ages 12–18.
A 2018 nationally representative survey found that 70% use their mobile device within 30 minutes of going to sleep.
Data suggests those who had spend more time on their screens were are likely to wake in the night from notifications on their phone, or experience disruptive sleep.
36% of Americans age 12-18 and 35% of Mexican teens age 13-18 woke up during the night before to check their mobile device.
For American children and teens, 54% of those did so because of getting a notification and 51% did so because of the desire to check social media.
Content that stirs emotions has been linked with a delay in the onset of sleep.
Using screens negatively impacts the adult sleep cycle, and using screens can also affect one’s physical health.
Obesity is a common result of spending great amounts of time on screens like a television, video games, smartphones, or a computer screen.
If the amount of screen time adolescents spend was limited, the likelihood of obesity can be reduced.
The associations between discretionary screen time and adverse health outcomes were strongest in those with low grip strength, fitness and physical activity and markedly attenuated in those with the highest levels of grip strength, fitness and physical activity.
Sedentary behavior is largely due to the nature of most electronic activities.
Sitting to watch television, playing computer games or surfing the Internet takes time away from physical activities which leads to an increased risk of weight gain.
It has been found that children (kindergarten and 1st graders) who watch 1–2 hours of television a day are more likely to be overweight or obese than children who watch less than one hour a day.
Additionally, one study showed that the increased use of video games and other forms of media consumption led to more back pain among Norwegian teens.
Screen time negatively affects health in children independently of their physical activity and eating habits.
The effect of advertising was demonstrated in a study where children were shown cartoons with and without food commercials: children who watched the food commercials along with the cartoons ate 45% more unhealthy snacks than the group who watched the cartoons without food ads.
Sleep and screen time are heavily impacted by the other and can lead to affecting one’s behavior as as one does not get an adequate amount of sleep, it can affect their behavior and performance for the day.
Excessive screen usages is linked with many mental health effects in children.
Social media use is linked with depressive symptoms among mostly girls and that recreational screen time is linked to negative psychological effects on children and teens.
With screen usage increasing as time progresses, adults have begun spending more and more time focusing their attention of screens and not their own kids.
This time spent sitting and viewing a screen has been linked to mental health effects such as anxiety and depression.
Adults who spend six hours or greater using screen time are more likely to suffer from moderate to severe depression.
Increased use in screen time has been shown to be directly correlated with an increased chance of depression in adults.
With this added risk, lack of sleep plays a major role in a healthy mindset, and without proper rest, mental health can degrade at a higher rate.
An increase in screen time has been associated with negative cognitive outcomes for children between 0 and 4.
A study on children aged 24–30 months old found that toddlers with 3 hours of TV viewing per day were three times as likely to experience a language delay.
Toddlers with higher TV time also scored lower on school readiness tests, which measured vocabulary, number knowledge, and classroom engagement.
The same outcomes are not present in children older than 4.
Children who watched more TV were found to have less brain connectivity between language, visual and cognitive control regions of the brain than their peers who watched less TV.
Preteens who spent over 7 hours on screens a day and children who spend less than 7 hours a day had noticeably different development of their cerebral cortex.
Academy of Pediatrics recommend for children in age 3 – 5, a screen time not longer than 1 hour per day.
Children who have a longer screen time, have slower brain development, what hurt skills like imagery, mental control and self-regulation.
The brain is developing most rapidly in the first five years, when brains are very plastic and soaking up everything, forming these strong connections that last for life..
Over exposure also hurts skills of literacy, cognition and language.
The primary behavioral effect of screen use is an increase in sedentary activity.
Approximately 47% of American children spend 2 or more hours per day on screen-based sedentary activities.
Children who had high amounts of screen time had delayed white matter development, decreased ability to rapidly name objects, and poorer literacy skills.
It has been proven that there is a negative relationship between an increase in screen time and behavioral problems in young children.
In these preschool aged children (between the ages of 0 and 5 years old) with over four hours of screen usages a day was shown to have 1.76 times more likely to have behavioral and conduct problems.
This is in contrast with the 25.5% who reported at least 20 minutes of physical activity per day for a week.
The likelihood of a child participating in physical activity has been shown to decrease with increasing screen use.
Screen use can also affect interpersonal skills.
Sixth-graders who went five days without screen use were significantly better at reading human emotions than sixth-graders with average screen use.
The excessive use of screen time in adolescents is linked with triggering dopamine, which is a neurotransmitter that acts as a reward system in the brain.
Leading to these children developing attention deficits, like ADHD (attention deficit hyperactivity disorder) and developing addictive tendencies on these young children.
Children who have extensive exposure to particularly violent media are at risk of developing aggressive behaviors and a desensitization towards violence.
Children that spend an increased amount of time on screens have less opportunities to interact with adults and caregivers which reduces their language development.
When children are spending most of their time using tablets and screens there are less chances for them to interact with adults, like their parents, to expand their language skill set.
Younger, preschool aged children and the amount of screen time they are exposed to has a negative effect on their language development.
When children are spending 2 or more hours on their screens, tablets, TV’s it is more likely for them to have a poor vocabulary and shows delays in when they are starting to speak.
A correlation between screen time and developmental and behavioral issues exists.
Out of the 28,484 preschool aged children in the study it was concluded that children with two or more hours of screen time a day showed to have 1.54 to 2.38 times more odds of having a speech disorder and had 1.96 times more likely to have a type of learning disability, then those children who had an hour or less of screen time per day.
Academic performance can be improved by screen time depending on the length and content of exposure.
The right content can prove beneficial, but too much screen time distracts students from studying.
Increased screen use has been associated with missing school assignments, and students who used screens for more than two hours a day are twice as likely to not turn in homework on a regular basis.
Children who lack guidance from their mothers are more likely to overuse screen time and also to struggle academically.
Those with more prevalent maternal interference in their online activities tend to have more controlled screen time, and these children also watched more educational content when online versus their counterparts with less parental control.
Educational content consumed during time allotted for digital use is shown to be positively associated with academic achievement.
Those who only consumed violent media or leisurely video games on school nights, showed a negative associated with academic achievement.
Their lower academic performances were marked by decreases in grade averages and in their ability to adjust to a school or academic environment.
Inability to adjust to these situations resulted in a negative effect on school performance.
More screen time generally leads to less time spent in nature.
Studies show nature-inspired activities simultaneously decrease for youth in financially stabilized countries with mental health issues increasing, drawing a connection to higher screen time levels.
There is no consensus on the safe amount of screen time for adults.
Many adults spend up to 11 hours a day looking at a screen.
Recommendations that help mitigate negative health effects include breaking up continuous blocks of screen time usage by stretching, maintaining good posture, and intermittently focusing on a distant object for 20 seconds.
Adults are encouraged not to eat in front of a screen to avoid habit formation and to keep track of their screen use every day, and replace some of the unnecessary usage with a physical activity or social event.
Guidelines about media use for children under 5:
Birth to age 1: No sedentary screen time
Ages 2–4 No more than 60 minutes of sedentary screen time
More extensive guidelines have been put forth by the American Academy of Pediatrics:
Birth up to 18–24 months: No screen time
18–24 months: Limit screen time as much as possible
Ages 2–5: Limit screen time to about an hour a day
The content should be high-quality, educational, slower-paced, and free of violence.
Caregivers should avoid giving apps to children that have highly distracting content.
Families should try to use media with their child so that they can help explain what content is on the screen and how it applies to their own lives.
They recommend to turn off devices when the child is not actively using them and to keep bedrooms as screen-free zones.
Additionally, they recommend that screens should be put away at least 1 hour before bedtime.
For children from ages 5 to 18, the AAP recommends children and teens should keep devices out of the bedroom during bedtime, and screens should be put away at least 1 hour before bedtime.
They recommend that caregivers discourage children and teens to use screens during homework for entertainment purposes, and to have a family plan that aligns with their family’s needs, values, and goals.
Thee plan should have consistent guidelines and limits for each family member, and families should consider having designated times of the day and areas in the house that are screen-free.
High and increasing use of addictive social media, mobile phones, and video games are common in early adolescence and are associated with suicidal behaviors and ideation and worse mental health.