UH OH: So Men Do Have a Biological Clock. “We’ve known for a while that fathers in their 40s pose an increased risk of conceiving children with birth defects, or passing down defective recessive genes through their children that are expressed in their grandchildren.  Added to this knowledge are recent studies that have been finding problems aren’t just physical, but mental.  A Malaysian study in 2011, and a just-released 2014 study from Sweden both found that older dads (i.e., age 40 or greater) conceived children who were several times more likely, even an order of magnitude more likely, to have various psychological disorders and mental illness. Unfortunately, when one considers the steadily rising average age of the Western mother, the burgeoning cohort of women who give birth after age 35 (14% in 2008, undoubtedly higher now), and that fathers are typically a few years older than mothers, it seems like a great many men, yours truly included, are conceiving children at age 40 and beyond, with a substantially higher risk of abnormalities, defects, and illnesses from advanced paternal age, if not maternal as well.”