Testosterone levels drop in mothers and fathers in response to their infant’s need for care


A study has found evidence that a drop in testosterone levels is associated with being actively needed for a caring task – in both women and men and to a similar extent in each.

The task was the ‘strange situation procedure’, which has been developed to test attachment security of infants. In this experiment, the researchers measured not just how the infant was responding, as is normal for this procedure, but how the parent was responding too, in particular what happened to their testosterone between the start and finish of the procedure. The strange situation test is a series of up to seven parent-toddler separations, followed by reunions. Attachment security on the part of the infant is measured by observing their reaction to separation and reunion – “secure” attachment is associated with some distress on separation, but not excessive, and that distress is fairly easily resolved once the parent returns.

The test is typically stressful for parents too, as they are able to watch what their child does when they walk out. (If a parent gets too concerned, the test is ended and the child is not left alone again.) Researchers found that, although men on average have higher levels of testosterone to start with, the drop in testosterone during the strange situation procedure was, on average, similar for each parent. Testosterone did not drop during a teaching task that followed the strange situation procedure – the drop was uniquely associated with the appeal to nurturing involved in the strange situation procedure.

Another observation from the research is that testosterone dropped less in fathers who were less comfortable with closeness and intimacy (‘avoidantly attached’). It is not clear why this was so for fathers and not for mothers who were similarly inclined. Perhaps the mothers in the experiment had more practice at caring (they reported higher involvement in caring on average than did the fathers) and were more confident in their ability to comfort the infant.

All these findings reflect earlier research. Lower testosterone in fathers is linked to more engagement in parenting, greater empathy in response to infant cries and more affection towards a partner. Exposure to caring stimuli, such as hearing a recording of infant crying, can lead to a drop in testosterone in fathers, although in experiments where the men are unable to respond to the cries, testosterone tends to increase through stress. There are, however, considerable variations between men, both in relation to their baseline levels of testosterone, and the extent to which levels change in caring situations. Other research has observed that testosterone levels change more in men who show greater sensitivity toward children.

In this experiment, 154 fathers and 146 mothers from Michigan, USA, participated five times surrounding the birth of their second child: once before the birth in the third trimester, then at 1, 4, 8 and 12 months after the birth. The strange situation procedure was conducted during the 12-month assessment.


Edelstein RS, Chin K, Saini EK, Kuo PX, Schultheiss OC & Volling BL (2019), Adult attachment and testosterone reactivity: Fathers’ avoidance predicts changes in testosterone during the strange situation procedure, Hormones & Behavior

Photo: David Jason Garcia. Creative Commons.