For decades, most family health research has centered on mothers. A new study from Penn State flips that expectation. It suggests that what fathers do with their babies and toddlers can shape a child’s heart and metabolic health years later, and the same clear link did not show up for mothers in this dataset.
Jennifer Graham-Engeland, a professor of biobehavioral health at the Penn State College of Health and Human Development and a co-author, admitted the team did not expect this split. “The lack of clear results based on the mothers’ co-parenting was not expected,” she said.
The research team included Alp Aytuglu (lead author and postdoctoral scholar at Penn State), Jennifer E. Graham-Engeland, Mark E. Feinberg, and Hannah M. C. Schreier (senior author). Their paper is titled Longitudinal associations between father and mother child interactions, coparenting, and child cardiometabolic health and was published online in Health Psychology.
Their goal was specific: track whether early parenting and coparenting patterns predict children’s later cardiometabolic health, including markers tied to inflammation and blood sugar control.
How the Study Was Done
The study used data from Penn State’s Family Foundations project, a randomized controlled trial focused on improving coparenting among first-time parents (ClinicalTrials.gov identifier NCT01907412).
Key details from the sample and design:
- The project started with 399 child-father-mother triads (intervention group 221, control group 178).
- The primary analytical sample described in the paper included 292 triads with the needed observational data.
- Families had to be first-time parents, at least 18, and living together. Participants were recruited through childbirth education programs and OB-GYN clinics in Delaware, Maryland, Pennsylvania, and Texas.
- Most parents were married (87%), most had a college degree or higher (83% of fathers and 94% of mothers), and most identified as non-Hispanic White (83% of fathers and mothers). Median household income was about $80,000 to $85,000.
Researchers visited families at three time points:
- Around 10 months old
- Around 24 months old
- Around 7 to 8 years old
At 10 and 24 months, parents did an 18-minute video-recorded interaction with their child. It included 12 minutes of free play with toys and 6 minutes of slightly challenging tasks like building a tower, stringing beads, or completing a puzzle. Trained coders then rated parenting and coparenting behaviors.
Later, when children were about 7, the team collected dried blood spot samples from a finger stick and measured four cardiometabolic indicators:
- Total cholesterol
- HbA1c (average blood sugar over about 2 to 3 months)
- Interleukin-6 (IL-6), related to inflammation signaling
- C-reactive protein (CRP), an inflammation marker produced by the liver
What They Measured in Parenting
The researchers focused on two big ideas.
First was sensitive engagement, which combined parenting behaviors such as engagement, positive affect, and sensitivity. Higher scores went to parents who showed warm, prompt, and age-appropriate responses, repeated positive emotions like love and tenderness, and genuine interest while participating with the child.
Second was competitive-withdrawn coparenting. This captured moments when parents competed for the child’s attention or one parent disengaged during shared interaction. The competitiveness and withdrawal ratings were combined into one composite.
To check consistency, some sessions were double-coded. Reliability scores were solid, with intraclass correlations reported between .73 to .79 for competitiveness and withdrawal, and between .76 and .82 for parenting dimensions across waves.
The Core Finding: Fathers’ Early Behavior Predicted Two Key Health Markers
A clear pattern showed up for fathers.
The study found that fathers who were more sensitive and engaged when their child was 10 months old were less likely to show competitive or withdrawn coparenting behaviors at 24 months. That later coparenting pattern then predicted child health at around age 7.
In the model, greater father competitive-withdrawn coparenting at 24 months predicted higher CRP and higher HbA1c years later. In plain terms, more conflict-like or disconnected coparenting behavior from fathers in toddlerhood lined up with higher inflammation and worse blood sugar control in second grade.
The statistical model for fathers fit well: χ²(58) = 76.538, p = .055, CFI = .95, RMSEA = .05.
The study also tested indirect pathways, and the indirect link from father sensitive engagement at 10 months to child CRP and HbA1c through father competitive-withdrawn coparenting at 24 months was significant.
The results did not show the same pattern for mothers. The mother model did not fit acceptably on some indicators: χ²(57) = 110.329, p < .05, CFI = .76, RMSEA = .08. And in that mother model, parenting and coparenting variables were not significantly associated with the child cardiometabolic outcomes at about age 7.
Why the Father Effect Might Look Bigger Here
The study does not claim mothers do not matter. Instead, it offers reasons this specific pattern could appear.
Graham-Engeland suggested the difference may reflect typical roles in many two-parent households. “In two-parent families like the ones in this study, the mother is frequently the primary caregiver,” she said. She added that mothers’ behavior may often represent the family norm, while fathers may either reinforce that norm or disrupt it.
The academic paper also offers additional explanations. It notes that toddlers might interpret a mother’s behavior differently because they are used to receiving attention from her in everyday interactions. The paper also raises the possibility that traditional masculinity norms, like emotional restraint and competitiveness, could show up as withdrawal or controlling behaviors in coparenting situations.
The discussion also points to the father vulnerability hypothesis, which suggests fathers may be more reactive to negativity in the coparenting relationship, increasing the chance that stress spills over into the rest of the family system.
Why CRP and HbA1c Stood Out, While IL-6 and Cholesterol Did Not
Two health measures were most tied to the father-related pathway: CRP and HbA1c.
The paper notes CRP is a broader and more stable marker of systemic inflammation than cytokines like IL-6, and it can reflect chronic stress effects more clearly. It also notes that although cholesterol and HbA1c are often related, HbA1c may be more sensitive to stress-related family dynamics when obesity-related factors are controlled. The models included child waist-to-hip ratio as a covariate because body composition strongly relates to cardiometabolic outcomes.
The researchers emphasized that this is not about praising one parent and blaming the other. It is about noticing how fathers can shape the environment in ways that last.
Hannah Schreier said the surprise is not that warmth is good, but how early it matters. “No one will be surprised to learn that treating your children appropriately and with warmth is good for them,” she said. “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.”
Lead author Alp Aytuglu stressed that fathers influence family dynamics in powerful ways. “Everyone in the family matters a lot,” he said, adding that in households where a father is present, dads can shape the environment in ways that support or undermine a child’s health for years.
Outside the study itself, the article also referenced broader work on coparenting. A 2023 study found children did best when both parents viewed coparenting as highly positive and worst when both viewed it as poor. In that earlier research, fathers again seemed to have an outsized effect when their view of coparenting was less positive than the mother’s. Sarah Schoppe-Sullivan, lead author of that study and president of the board of the Council on Contemporary Families, said that gap “may lead to more conflict between the parents, more disagreement on parenting decisions, and less positive engagement between fathers and their children,” and that these dynamics may contribute to poorer child adjustment.
Real-World Consequences: What This Could Mean for Families and Policy
If these findings hold up across more diverse families, they point toward a practical takeaway: early father involvement is not optional fluff. It may be part of long-term prevention for inflammation and metabolic risk in children.
The study argues that programs that support positive father-infant interactions and reduce coparenting conflict could be valuable preventive strategies. The Family Foundations program itself was designed to strengthen coparenting through prenatal and postnatal classes, and the paper suggests that better access to support services for fathers could help improve child health outcomes.
The bigger message, according to Aytuglu, is about support, not shame. “Fathers, alongside mothers, have a profound impact on family function that can reverberate through the child’s health years later,” he said. “As a society, supporting fathers and everyone in a child’s household is an important part of promoting children’s health.”
Limits of the Study and What It Does Not Prove
The researchers clearly stated limits:
- The sample was mostly White, higher-income, higher-education, two-parent households with first children, so the findings may not generalize to single-parent families, same-sex parents, grandparents raising children, or families with multiple children.
- The study relied on observed interactions in structured sessions, not every moment of everyday life.
- The models could not successfully combine mother and father dynamics into one integrated model due to poor fit, limiting conclusions about how both parents’ behaviors work together.
Even with those limits, the results challenge a common habit in parenting research: treating fathers as secondary characters. In this dataset, dads were not background noise. Their early engagement and their role in coparenting dynamics lined up with measurable differences in children’s inflammation and blood sugar years later.
