When it comes to raising children, parents are often given simple messages: less screen time is better, more exercise is better, and the right early education will give children a head start.
But two long-term studies suggest the picture may be more complicated.
One 20-year study of almost 400,000 students found that children who attended public-school pre-K (in Ireland known as ECCE (Early Childhood Care and Education) settings like Creches, Montessori and the like went on to achieve higher grades and test scores throughout their school years than children who experienced other forms of early childcare.
Meanwhile, an eight-year Finnish study found an unexpected association between screen use and cognitive performance: children who accumulated more screen time as they grew up tended to show better cognitive processing during adolescence.
Neither study suggests that one approach is automatically best for every child. Instead, the findings point towards a more nuanced message: what children do, who they learn from and the quality of their experiences may matter more than simple rules about screens, exercise or childcare.
A head start that lasted into the teenage years
The 20-year study, led by George Mason University and overseen by Charles Bleiker, associate professor of teaching and learning at Florida International University, followed almost 400,000 Miami-Dade County public-school students from third grade through high school.
Researchers compared children who had attended public-school pre-K4 with those who had experienced other forms of early childcare. Pre-K4
Students who had attended public-school pre-K4 subsequently achieved higher grades and performed better on standardised tests throughout their school years. The differences continued into adolescence.
One possible explanation was the level of teacher preparation.
The researchers compared public-school pre-K with centre-based daycare and home-based childcare providers participating in the Early Learning Coalition. While all met minimum standards, public-school pre-K teachers were required to have a college degree.
The researchers suggest that teachers with greater preparation in areas such as child development and classroom management may be better equipped to create stimulating learning environments and support children through behavioural or developmental challenges.
Early exposure to structured classroom routines may also help children become familiar with the expectations of formal education before they start elementary school.
For parents in Ireland, the findings are interesting but should not be interpreted as evidence that one particular type of ECCE (Early Childhood Care and Education) setting is automatically better than another. The US study was conducted in Miami-Dade County, so its results cannot simply be applied to Irish preschools, Montessori schools, crèches or childcare centres.
Instead, it highlights factors parents may want to consider, including staff qualifications and experience, stability, the quality of interactions with children and how stimulating and supportive the environment is.
And then there’s the screen-time surprise
The Finnish research adds another unexpected piece to the puzzle.
Researchers followed children for eight years as part of the PANIC study, examining physical activity, sedentary behaviour and screen use from childhood into adolescence.
The analysis included 260 young people — 124 girls and 136 boys — who were an average age of 15.8 years.
Rather than finding that more screen time was associated with poorer cognitive performance, the researchers found that greater screen time beginning in childhood was associated with better cognitive processing during adolescence.
That may sound surprising given the amount of attention usually given to the potential harms of screen use.
However, the researchers stress that the study does not show that screen time causes better cognitive performance. It is possible that the type of activity children were doing on screens played an important role.
It's not just how much screen time — it's what they're doing
According to doctoral researcher Petri Jalanko from the University of Jyväskylä, the findings suggest that parents and teachers should think about the nature of children's screen activities rather than treating all screen time as equally harmful.
Screens can be used for passive entertainment, but they can also be used for learning, creativity, problem-solving and other activities that require active mental engagement.
That distinction could be important when thinking about children's digital lives.
The researchers' overall message is not that children should spend more time on screens, but that screen use should be considered alongside other activities and that balance matters.
Exercise and brain health are more complicated too
The relationship between physical activity and cognitive performance was less straightforward.
Among girls, greater amounts of light-intensity physical activity from childhood were associated with better working memory during adolescence.
Among boys, greater participation in guided physical activity was associated with better working memory.
The researchers also found an unexpected association between lower levels of self-reported unsupervised physical activity and better cognitive processing.
However, physical activity and sedentary time measured objectively using a device that tracked heart rate and movement were not associated with cognitive processing.
The researchers suggest that one reason may be that activity monitors cannot tell researchers exactly what a child is doing during periods of movement or inactivity.
What does this mean for parents?
Taken together, the two studies reinforce a useful message: there probably isn't a single magic formula for raising healthy, happy and capable children.
Early learning environments matter, but the quality of the environment and the people working in it may be more important than simply choosing one category of childcare.
Screen time isn't necessarily one-dimensional either. What a child is doing on a device may matter as much as the number of minutes spent using it.
And physical activity remains important, but its relationship with cognitive development appears to depend on factors such as the type, intensity and context of the activity.
For parents, that could mean focusing less on rigid rules and more on creating a balanced day that includes:
- Positive early learning experiences with supportive, well-trained educators.
- Active play and physical activity appropriate for the child's age.
- Screen activities that encourage learning, creativity and problem-solving, rather than relying solely on passive entertainment.
- Time away from screens for sleep, family interaction, outdoor play and social development.
- A supportive and stimulating environment where children can develop academically, socially and emotionally.
The important caveat
Both studies have limitations, and neither proves cause and effect.
The Finnish research found associations between screen use, physical activity and later cognitive performance. It does not establish that giving a child more screen time will improve their cognitive abilities.
Similarly, the US pre-K research cannot prove that attending public-school pre-K itself caused the later academic differences.
The researchers behind the Finnish study say further intervention research is needed to understand cause and effect, including why associations may differ between boys and girls.
What these studies do offer is a reminder that children's development is complex — and that quality, context and balance may be more important than simple rules about what children should or shouldn't do.
Story Sources:
- Materials provided by Florida International University. The Influence of Elementary School Quality on Differential Long-Term Effects of Preschool. Early Childhood Research Quarterly, 2026; 76: 157
- University of Jyväskylä - Jyväskylän yliopisto. Associations of Physical Activity and Sedentary Time From Childhood to Adolescence With Cognition in Adolescence: The PANIC Study. Pediatric Exercise Science, 2026; 38 (3): 268