Do Boys Really Move More Than Girls? What the Research Says

Updated October 2026 · 11-minute read · by Yegor Nadvornyy, founder of Brainrich Kids

A video is going around Instagram that says boys move 25% more than girls because their brains develop differently. It's a claim that feels true to a lot of parents who have watched a son bounce off the couch while a daughter builds a block tower. So we went to the research: the large accelerometer studies, the infant meta-analyses, the brain-imaging work and the studies on how parents treat sons and daughters. Half of the claim holds up. The other half doesn't, and that half matters more for how you raise your kids.

Jump to: The real numbers · When the gap starts · The brain claim · What parents add · Your child isn't an average · What to do at home · FAQ

Do boys move more than girls? The real numbers

The best data on how much children move comes from accelerometers, small motion sensors kids wear on a belt for several days. They count movement all day without anyone's opinion getting in the way. Two big projects have pooled this data from many countries.

The International Children's Accelerometry Database (ICAD) combined sensor data from 27,637 children and teens aged about 3 to 18 in ten countries. Cooper and colleagues reported in 2015 that boys were more active and less sedentary than girls at every age they looked at.

A 2023 follow-up by Kretschmer and colleagues used the same database to ask a sharper question: not just "who moves more on average," but how the whole spread of movement differs. With 15,461 children from nine countries, they found:

So the Instagram number is in the right neighborhood if it means total movement. The gap lives almost entirely in the fast, hard, out-of-breath kind of play. Girls and boys spend about the same time walking around, playing calmly and sitting.

The same pattern shows up in preschoolers. A 2023 meta-analysis by Bourke and colleagues pooled 48 accelerometer studies covering 20,078 children aged 3 to 5. Girls were about 23% less likely than boys to meet the World Health Organization's full activity recommendation for that age, and less likely to hit the 60-minute daily target for energetic play. For total activity, the difference between boys and girls was small and not statistically significant.

When does the difference start?

If the difference were purely learned, you'd expect babies to look the same. They mostly do, but not completely.

In 1999, Campbell and Eaton ran a meta-analysis of 46 studies of infants, with 78 boy-versus-girl comparisons. Baby boys were more active than baby girls, but by a small amount: about 0.2 standard deviations on objective measures. In plain terms, if you lined up a room of baby boys and a room of baby girls, the two groups would overlap by roughly 90%. Parent reports showed an even smaller gap.

A 2024 study from the US Midwest, posted as a preprint by Kwon and colleagues, put accelerometers on 137 toddlers aged 10 to 16 months. Boys averaged 238 minutes of total activity a day and girls 221, a gap of about 7%. Energetic activity didn't differ significantly. The gap wasn't explained by motor skills or by the parenting practices the researchers measured.

By school age the gap is wider. Eaton and Enns's 1986 meta-analysis of motor activity found that boys' higher activity level grows from infancy into childhood. Campbell and Eaton's view, after reviewing the infant data, was that the early difference is likely biological, and that expectations, experiences and later biological changes then amplify it into the bigger childhood gap.

Age	What studies found
Infants	Boys slightly more active, about 0.2 standard deviations (46 studies)
10 to 16 months	Boys about 7% more total activity; vigorous activity not significantly different (137 toddlers)
Ages 3 to 5	Girls about 23% less likely to meet the full WHO activity recommendation (48 studies)
Ages 3 to 18	Boys about 20% more total movement and 38% more vigorous activity (15,461 children)

Is it because boys' brains develop differently?

This is the part of the claim that doesn't hold up, at least not in the simple form it's usually told.

Brains do grow on different timelines. The largest long-term brain-scan study of children, by Lenroot and colleagues at the US National Institute of Mental Health, followed 387 young people aged 3 to 27 with 829 MRI scans. Total brain volume peaked at about 10.5 years in girls and 14.5 years in boys, and gray matter peaked 1 to 2 years earlier in girls. That study measured size and timing. It did not test whether those differences make boys move more.

Beyond size, boy and girl brains are far more alike than different. In 2021, neuroscientist Lise Eliot and colleagues reviewed three decades of the largest brain-imaging studies. Male brains are larger on average, about 11% in adults, and that size difference explains most of the other reported differences. Once size is accounted for, sex explains only about 1% of the variation in brain structure, and most claims of a "male brain" and a "female brain" have not held up when other teams tried to repeat them.

Body maturity seems to play a part. Girls mature physically earlier than boys, and children's activity level tends to drop as they mature. Eaton and Yu tested this in 1989 with 83 children aged 5 to 8. Girls were both more physically mature and less active, and maturity explained part of the gap. The difference got smaller once maturity was counted, but didn't disappear.

Hormones before birth may play a part. Girls with congenital adrenal hyperplasia (CAH), a condition that exposes them to higher levels of male-typical hormones before birth, offer a natural experiment. In a 2007 study by Pasterski and colleagues, mothers rated 38 girls with CAH as more active than their unaffected sisters. A 2011 study from the same group found girls with CAH preferred more boy-typical play styles. The researchers noted that earlier results on activity level had been inconsistent, and these were mother-reported, not measured with sensors.

What parents add to the gap

Here's the part that tends to surprise people. Adults start treating boys and girls differently around movement before children can walk.

In a 2000 study at New York University, Mondschein, Adolph and Tamis-LeMonda asked mothers of 11-month-old babies to predict how steep a slope their baby could crawl down. Mothers of girls underestimated their daughters. Mothers of boys overestimated their sons. Then the researchers tested the babies on the same slopes. Girls and boys crawled at identical levels. The mothers' beliefs had no basis in what the babies could do.

In another 2000 study, Morrongiello and Dawber showed mothers videos of their own children doing risky things on a playground and asked them to react as they would in real life. Mothers of daughters judged the same activities as riskier, stepped in more often and faster, and gave more warnings about getting hurt. Mothers of sons gave more encouragement to keep going.

None of this means parents are doing something wrong. These are loving, protective instincts. But a girl who hears "be careful" every time she climbs, and a boy who hears "you've got it," get different practice over thousands of small moments. Over years, that kind of difference can add up to a gap a sensor can see.

Your child isn't an average

Averages hide how much boys and girls overlap. Developmental psychologist Warren Eaton, who led much of the classic activity-level research, put it this way: the typical boy and the typical girl differ little. The difference shows up at the edges, where the most active child in a group is more likely to be a boy and the least active more likely to be a girl.

The 2023 ICAD study found the same thing from another angle. Boys didn't just average more vigorous play. They were also far more spread out, with 30% more variation from one boy to the next. Plenty of boys are calm. Plenty of girls are the fastest kid on the playground.

So if your daughter climbs everything in the house, she's not unusual. If your son would rather read than run, he's not either. The research describes groups. It can't tell you what your child needs.

What this means at home

Whatever starts the gap, the fix runs the same way: make energetic play easy, daily and expected for every child.

We love outdoor play and always will. A home climbing gym covers the hours when outside isn't an option: the heat of July, January darkness at 5 pm, mosquito season, the half hour before dinner. It also takes the "boy toy" label off climbing, because it's simply part of the living room. For more on letting kids take small, managed risks, see controlled risky play.

A place to climb, for every kid in the house

The Spider V3 has monkey bars, pull-up bars, rings, a rope and a net, so a cautious climber and a fearless one can both find their level. The Spider Max V3 adds a second span for siblings. Both are steel, rated for 220 lb and tension-mounted between floor and ceiling with no drilling. More than 10,000 families have a Brainrich gym at home, and occupational and physical therapists in our owner community recommend them. As with any climbing, an adult stays in the room and a mat goes under the bars.

Frequently asked questions

Are boys more active than girls? On average, yes. In a database of 15,461 children from nine countries, boys logged about 20% more total movement and 38% more moderate-to-vigorous activity. Girls and boys spent about the same time in light activity and sitting. The two groups overlap a lot, and many girls are more active than many boys.

Do boys move 25% more than girls? We found no study behind the exact 25% figure. The closest large study found about 20% more total movement in boys, with the difference concentrated in vigorous play like running and climbing.

Is the difference caused by boys' brains? Not in any simple way. Brain growth peaks later in boys, but beyond overall size, boy and girl brains are much more alike than different, and no study we found tied a brain difference to a set amount of extra movement. Body maturity, hormones before birth, how adults treat boys and girls, and children's surroundings all appear to play a part.

At what age do boys become more active than girls? A small difference, about 0.2 standard deviations, appears in infancy. In one study of toddlers aged 10 to 16 months, boys had about 7% more total activity. The gap grows through the preschool and school years.

How can I help my daughter be more active? Make energetic play easy and expected: something to climb, time to run, and the same encouragement you'd give a son. Swap "be careful" for questions that help her plan her next move, and stay close without stepping in too soon.

Sources

Kretschmer, L., Salali, G.D., Andersen, L.B. et al. (2023). Gender differences in the distribution of children's physical activity: evidence from nine countries. International Journal of Behavioral Nutrition and Physical Activity, 20. · Cooper, A.R., Goodman, A., Page, A.S. et al. (2015). Objectively measured physical activity and sedentary time in youth: the International children's accelerometry database (ICAD). International Journal of Behavioral Nutrition and Physical Activity, 12. · Bourke, M., Haddara, A., Loh, A. et al. (2023). Adherence to the World Health Organization's physical activity recommendation in preschool-aged children: a systematic review and meta-analysis of accelerometer studies. International Journal of Behavioral Nutrition and Physical Activity, 20. · Campbell, D.W., Eaton, W.O. (1999). Sex differences in the activity level of infants. Infant and Child Development, 8(1). · Kwon, S., Welch, S., Capan, S. (2024). Sex Differences in Physical Activity of US children at age 13 months: Child and Mother Physical Activity Study (CAMPAS). Research Square preprint. · Eaton, W.O., Enns, L.R. (1986). Sex differences in human motor activity level. Psychological Bulletin, 100(1). · Eaton, W.O., Yu, A.P. (1989). Are sex differences in child motor activity level a function of sex differences in maturational status? Child Development, 60. · Lenroot, R.K., Gogtay, N., Greenstein, D.K. et al. (2007). Sexual dimorphism of brain developmental trajectories during childhood and adolescence. NeuroImage, 36(4). · Eliot, L., Ahmed, A., Khan, H., Patel, J. (2021). Dump the "dimorphism": Comprehensive synthesis of human brain studies reveals few male-female differences beyond size. Neuroscience & Biobehavioral Reviews, 125. · Pasterski, V., Hindmarsh, P., Geffner, M. et al. (2007). Increased aggression and activity level in 3- to 11-year-old girls with congenital adrenal hyperplasia (CAH). Hormones and Behavior, 52. · Pasterski, V., Geffner, M.E., Brain, C. et al. (2011). Prenatal hormones and childhood sex segregation: playmate and play style preferences in girls with congenital adrenal hyperplasia. Hormones and Behavior, 59. · Mondschein, E.R., Adolph, K.E., Tamis-LeMonda, C.S. (2000). Gender bias in mothers' expectations about infant crawling. Journal of Experimental Child Psychology, 77. · Morrongiello, B.A., Dawber, T. (2000). Mothers' responses to sons and daughters engaging in injury-risk behaviors on a playground: implications for sex differences in injury rates. Journal of Experimental Child Psychology, 76. · Eaton, W.O. Motor activity level, University of Manitoba research page. · World Health Organization (2020). WHO guidelines on physical activity and sedentary behaviour; WHO (2019), guidelines for children under 5.