Relationship status, fatherhood, and how invested men are in taking care of their children, all have significant impact on their testosterone levels. An extensive scientific study shows chances of marrying and having a child are higher for those with higher T levels. However, the levels drop right after they become father, before returning to normal.
However, did you know being a father, and how much you involve in childcare, may affect testosterone levels?
One study carried out in more than 600 men in Philippines showed testosterone levels dipped in dads and more so for those actively involved in their child’s care.
That’s a strong motivation for dads to get out and spend time in the gym to compensate for nature’s way of lowering testosterone levels.
This study also shows that more men with higher testosterone levels ended up marrying and having a baby. That may be because men with higher testosterone levels are likely to have stronger muscles, better health, and ‘manly’–features that are more attractive in finding a partner.
However, one of the biggest surprises of this study is that testosterone levels after marriage decline significantly in comparison to those staying single. The levels decline even more for those who became fathers.
And fathers who spent longer hours caring for babies had the lowest testosterone levels.
This isn’t the first such observation. One study of US Army veterans showed testosterone levels in married men were lower than unmarried veterans.
Another study from Beijing, China found that married fathers had lower testosterone levels than non-fathers and unmarried men.
More from our research summaries:
All About Testosterone – everything about low T
Testosterone and Aging – Role of T over age
All About Cortisol – latest research on the stress hormone
All About Vitamin D – a concise review of symptoms & impact
CRP and Heart Risk– read about low inflammation, CRP, and risk of heart disease
Hormones and behavior go hand in hand, and influence each other.
Just take the example of public speaking. Right before the speech you will see a spike in cortisol and adrenal hormones. That’s a classic case of our body in fight or flight mode.
Another good example is the change in behavior during puberty when hormones (e.g., testosterone) start to rise. Data from a study of US Air Force veterans showed the testosterone levels increased around the time of divorce.
This behavior is not just in humans or primates. In fact, studies from birds (dark eyed juncos from North America) suggest that male testosterone levels increase during male-male competition and courtship, but reduce during long-term relationships and paternal care.
This brings us to two main conclusions. First, a testosterone test should consider partnership status, fatherhood, and time invested in paternal care. Next time you see a status change of a friend on your favorite social media, it might be worth looking for these subtle physiological factors.
The second part is even more important and remains unanswered: what’s the impact of men taking testosterone gel or patch on forming partnership and paternal relationship?
The figure above shows drop in testosterone levels for fathers at different time periods.
In new fathers, the highest decline in Testosterone levels are in first few months.
Here is a key summary of this study:
A total of 624 men with an average age of 26 years were studied (in 2009 & previously in 2005 to collect testosterone levels before they became partners or fathers).
First saliva sample was collected around 10:15 pm & second sample at 6:30 am.
Testosterone levels from single to married fathers dropped from 207 pg/ml to 153 pg/ml in morning and from 125 pg/ml to 84 pg/ml in evening.
Men with partnered fathers had a decline of 26% in morning & 34% in evening testosterone levels compared to normal age related decline of 12% in morning & 14% in evening (from 2004 to 2009).
The newly partnered men, who didn’t father any children, showed decline of 10% in morning & 32% in evening.
Longitudinal evidence that fatherhood decreases testosterone in human males by Lee T. Gettler et. al., PNAS 2011 Sep, 108 (39) 16194.
The descent of a man’s testosterone (and links therein) by Peter B. Gray, PNAS 2011 Sep, 108 (39) 16141.