Screen Time's Dangers: From Brain Development to Heart Health

A toddler plays with an iPad as her mother pushes her in a stroller. The child ignores her surroundings, mesmerized by the device.

A preteen plays Fortnite with his online friends. Most of these friends he doesn't know personally; he only knows them online.

A group of adolescents is seated in a booth at a restaurant. They haven't acknowledged each other or said a thing to their friends because they are power scrolling on TikTok.

A college student walks along a busy road focused on her phone. She narrowly misses being hit by a passing car.

We have all witnessed scenes like these in person or in the news. Should parents be concerned?

Source: Firefly AI generated image/Bredehoft

Screen Time by the Numbers

Did you know that toddlers (age 2 to 5) spend approximately 3.5 hours a day glued to a screen? It goes up from there by age. Children aged 8 to 10 spend on average 6 hours a day, and 11- to 14-year-olds 9 hours a day, while older teens (15 to 18) use screens for an average of 7.5 hours a day. If screen time for homework were included, the numbers would be much higher, according to the American Academy of Child and Adolescent Psychiatry. Almost all teens (95 percent) ages 13 to 17 have a smartphone. The most popular online platform for teens is YouTube. Nine-in-ten teens (90 percent) report using the site, followed by TikTok (63 percent), Instagram (61 percent), and Snapchat (55 percent). According to a 2025 survey by Common Sense Media, 72 percent of teens have used AI companions at least once, and about a third of teens use AI companions for romantic interactions, emotional support, and friendship.

Too much screen time may lead to a variety of physical and psychological problems.

Screen Time and Young Children's Brain Development

It is estimated that 90 percent of your child's brain development happens in the first five years of life. Screen time may pose a real danger to young brains. Consider the following:

• Reduced Real-World Interaction. Talking, playing, and exploring are critical to brain development. Screen time replaces real-world face-to-face interactions that are necessary for early brain development.
• Delayed Language Development. Conversations with adults and other children stimulate language development. Young brains need interactive conversations for language skills to develop, which is something viewing a passive screen cannot give a child.
• Overstimulation. Screens overstimulate the young brain, particularly the visual cortex, while the auditory cortex suffers. The auditory cortex is vital for developing social skills and language.
• Brain Structure and Function. Research shows links between screen time and negative impacts on the brain structure. A National Institutes of Health study found children with more than seven hours a day of screen time experienced thinning of the brain’s cortex, the area of the brain related to critical thinking and reasoning.
• Book Reading vs. Screen Time. A recent study shows that children's brains function differently when a book is read to them compared to seeing and hearing it from a screen. Specifically, significant activity occurred in the right temporal-parietal junction of the children's brains. The researchers believe that live book reading engages the part of the brain that is responsible for socially oriented cognitive processes, which focus on the reader's emotions, intentions, and shared attention. This provides an explanation for why live book reading and screen time may impact language development in different ways in young children.

Screen Time and Heart Health Risks to Your Child

Source: Kampus/Pexels

The more time children spend on smartphones, the greater the risk of heart disease, according to a new study reported in the Journal of the American Heart Association. This is true for both young children and adolescents. Each additional hour they spend on screen time is linked to a cluster of cardiometabolic risks, such as high blood pressure and obesity. This appears logical since the more hours children spend on an iPhone or iPad, the fewer hours they are involved in physical activity. The only thing that can significantly moderate excessive screen time is sleep duration. Short sleepers were at greater risk compared to long sleepers.

Screen Time and Social-Emotional Skills

Research indicates that high levels of screen time are associated with a variety of social and emotional problems in children and adolescents.

• Developmental Delays. One-year-olds exposed to more than four hours of screen time per day showed delays in communication and problem-solving at ages 2 and 4. High screen time for 1-year-olds was associated with developmental delays in fine motor, personal, and social skills at age 2.
• Executive Function. Preschoolers who had high levels of screen use scored lower on (1) the ability to suppress impulsive behaviors, (2) cognitive flexibility, which enables one to solve problems creatively, and (3) managing emotions and thoughts (e.g., a child who waits patiently instead of grabbing a toy).
• Social and Emotional Problems. A recent meta-analysis of 32 studies involving 26,266 students found that problematic social media use was significantly associated with a number of mental health concerns, including anxiety, depression, loneliness, low self-esteem, and fear of missing out (FoMO).

AI Companions for Advice, Friendship, and Emotional Support

It's not uncommon to have an imaginary friend when you are young. As a matter of fact, it is so common that 65 percent of children have had an imaginary friend at some point in their lives by age 7. However, AI has taken the "imaginary friend" to a whole new level. When I asked Google's AI feature if AI companions can speak, this is the response I got. "AI companions can speak to you using human-like voices, in addition to communicating via text."

Source: olia danilevich/Pexels

Do Teens Use AI Companions?

The answer is yes, according to a new survey by Common Sense Media.

• 72 percent of teens have used AI companions at least once.
• 52 percent of teens say they interact with AI companions a few times a month.
• 13 percent of teens use AI companions daily (8 percent several times a day; 5 percent once a day).
• 21 percent of teens report using AI companions a few times a week, which is the most common pattern.
• Boys were slightly more likely to say they had never used an AI companion than girls (31 percent vs. 25 percent).

Why do teens talk with these companions in conversations that feel personal and meaningful?

According to the Common Sense Media survey:

• They chat about their day, interests, or anything on their mind.
• They talk through feelings or get a different perspective when they're dealing with something tough.
• They can create or customize a digital companion with specific traits, interests, or personalities.
• They can role-play conversations with fictional characters from their favorite shows, games, or books.

Parenting Essential Reads

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Understanding the Danger of Misinformation in the Manosphere

What Are the Harms of Using an AI Companion?

There is the potential of serious harm. Take the case of Adam Raine.

Sixteen-year-old Adam Raine had suicidal thoughts and was in crisis last April. After extended conversations with his AI companion on ChatGPT, he took his own life. When his parents looked through his phone, they discovered that he had confided his suicidal thoughts to the AI companion. They also discovered that the AI companion discouraged him from telling his parents and even offered to write his suicide note.

It is clear to me that there are many positive things that can come from the AI revolution, but there can be negative things too.

Should we be raising our children on smartphones and tablets? If so, should parents put guardrails in place?

Practice Aloha. Do all things with love, grace, and gratitude.

© 2025 David J. Bredehoft