Weather 
They’re doing more than cracking dad jokes.
A new study suggests a father’s parenting behaviors in the early years of a child’s life may shape their physical health years down the line.
But in a surprising twist, researchers found no similar link when it came to mothers.
“The lack of clear results based on the mothers’ coparenting was not expected,” Jennifer Graham-Engeland, a professor of biobehavioral health at the Penn State College of Health and Human Development and co-author of the study, said in a statement.
There may be multiple factors at play, but some researchers suspect the split comes down to how moms and dads typically divide parenting duties.
“In two-parent families like the ones in this study — the mother is frequently the primary caregiver,” Graham-Engeland said. “So, it is possible that whatever the mother’s behavior, it tends to represent the norm in the family, whereas the father’s role tends to be one that reinforces the norm or disrupts it.”
The study drew on data from Penn State’s Family Foundations project, looking at 399 US families made up of a mother, father and their first child. Most were non-Hispanic white and had higher-than-average income and education.
When the children were 10 and 24 months old, researchers visited the families’ homes and filmed short play sessions with both parents.
Trained evaluators scored moms and dads on factors like warmth, responsiveness and whether their reactions were appropriate for the child’s age, plus co-parenting dynamics — especially when parents competed for the child’s attention rather than cooperating.
Years later, when the children turned seven, researchers returned and collected dried blood samples, which they used to measure four indicators of heart and metabolic health:
- Cholesterol
- Glycated hemoglobin (HbA1c), which reflects average blood sugar over two to three months
- Interleukin-6 (IL-6), an immune-system messenger tied to inflammation
- C-reactive protein (CRP), an inflammation marker produced by the liver
They uncovered a clear pattern: A dad’s behavior in infancy and toddlerhood echoed years later in his child’s body.
Fathers who showed less sensitivity when their baby was 10 months old were more likely to engage in competitive or withdrawn parenting by age two. And kids exposed to that behavior showed higher levels of inflammation and poorer blood-sugar control by age seven.
“No one will be surprised to learn that treating your children appropriately and with warmth is good for them,” said Hannah Schreier, associate professor of biobehavioral health and senior author of the study.
“But it might surprise people that a father’s behavior before a baby is old enough to form permanent memories can affect that child’s health when they are in second grade,” she continued.
Past research has linked growing up in high-conflict households to health problems in kids — including obesity, inflammation and trouble regulating blood sugar. But most of those studies focused on moms.
Here, when researchers examined maternal behavior, they found no significant link between a mother’s warmth or co-parenting style in infancy and a child’s health measures years later.
That doesn’t mean moms aren’t having an effect.
“Everyone in the family matters a lot,” said Alp Aytuglu, a postdoctoral scholar at Penn State and lead author of the study.
“Mothers are often the primary caregivers, and children are experiencing the most growth and development,” he explained. “The takeaway here is that in families with a father in the household, dads affect the environment in ways that can support — or undermine — the health of the child for years to come.”
If that’s true, American dads may have some catching up to do.
While most men and women say parenting should be shared equally, research shows moms still spend nearly twice as much time caring for their children as dads.
And it’s not just about who does the work. How parents view each other as co-parents also matters.
A 2023 study found kids have the best outcomes when both parents viewed their co-parenting relationship as highly positive — and the worst outcomes when both saw it as poor.
Fathers again appeared to have an outsized impact when their view was less positive than the mother’s.
“That may lead to more conflict between the parents, more disagreement on parenting decisions, and less positive engagement between fathers and their children,” said Sarah Schoppe-Sullivan, lead author of that study and president of the board of the Council on Contemporary Families.
“All that may play a role in their children’s poorer adjustment.”
Other research has also shown that children with involved, affectionate fathers tend to be less aggressive, more emotionally stable and have higher self-esteem, better social skills and greater confidence.
The researchers noted every family is different, and everyone in the household can influence a child’s health. The study is limited because it only looked at two-parent, first-child households — so the results could differ in families with single parents, grandparents, same-sex parents or more children.
Still, the message is clear: dads matter.
“Fathers, alongside mothers, have a profound impact on family function that can reverberate through the child’s health years later,” Aytuglu said. “As a society, supporting fathers — and everyone in a child’s household — is an important part of promoting children’s health.”
