A new study has found that testosterone and cortisol levels are associated with parental caregiving quality in fathers. The findings appear in the journal Psychoneuroendocrinology.

“Father involvement in parenting is on the rise, but research on quality of caregiving in fathers is very scarce. And although the role of hormones in parents is becoming more clear in the past decade, in fathers it has hardly been investigated,” said study author Peter A. Bos of Utrecht University.

“Therefore we wanted to investigate how steroid hormones such as cortisol and testosterone would affect the quality of caregiving in both fathers and mothers. My previous research has been on the role of hormones in human social behavior more broadly, and I am currently specializing in human caregiving behavior.”

The study examined 88 expectant mothers and 57 of their partners. The participants first visited a lab during the third trimester of pregnancy. They provided saliva samples before and after interacting with an unsoothable crying simulator infant for 15 minutes.

The researchers then visited the parents at home when the infant was 6 weeks old. The parents again provide saliva samples, and were asked to undress, change the diaper, and redress their child.

Train observers, who were not otherwise associated with the study, rated the sensitivity and cooperation of the parents during both interactions with the infants.

The researchers found interactions between cortisol and testosterone levels were associated with caregiving quality in fathers, but not mothers. Among fathers with higher testosterone levels, higher cortisol levels were associated with reduced sensitivity towards their child. In addition, higher cortisol levels during the prenatal period were also associated with a lower quality of postnatal caregiving in fathers.

“Hormonal responses in expectant fathers are related to how they behave towards their child. Even with the best intentions, a parent’s biology also plays an important role. Such relations can already be observed before the baby is born,” Bos told PsyPost.

“Being aware of this might be able to help fathers in parenting situations which are stressful. We know that stress does not help in being sensitive towards your child, and it might be more difficult if your hormonal systems respond stronger when dealing with the situation.”

“Being high in testosterone, with strong responses of cortisol will not make you a poor parent, but you might benefit from some extra time, or anything else that can help you deal with stress, or avoid it if possible,” Bos said.

But the study — like all research — includes some limitations.

“We need to replicate this study in larger and more diverse samples, as this is the first time this exact relation has been observed in fathers,” Bos explained.

“Another thing is that for ethical reasons we can only observe controlled and safe situations that are stressful. An important question is whether the observed relation with lower quality of caregiving also extends to maltreatment and abusive parenting styles. Scientifically, this question is much more difficult to answer.”

“Another issue is that we included ‘only’ two steroid hormones, whereas most research only includes one. But there are a dozen endocrine factors that we assume are relevant in human parenting behavior, most of them hardly investigated in humans. It is a nice start, but there is a lot more work to be done!”

“The lack of findings among mothers does not imply that endocrine factors are not relevant (based on the literature I would suggest the opposite), but in our sample most mothers were breastfeeding, which might function as an endocrine stress-buffer,” Bos added.

“Also, these mothers were more experienced in interacting with the child as compared to the fathers, feeling more secure about themselves and less stressed when being observed with the child.”

The study, “Prenatal and postnatal cortisol and testosterone are related to parental caregiving quality in fathers, but not in mothers“, was authored by Peter A. Bos, Christine Hechler, Roseriet Beijers, Kazuyuki Shinohar, Gianluca Esposito, and Carolina de Weerth.