Here is a video of John Gray speaking at Google. He speaks about testosterone in men and how it is released by problem solving and helps men relax. He mentions that men die on average a year after retiring from their jobs because they are no longer solving problems and getting their testosterone fix. They have low testosterone levels and then get a heart attack. Women on the other hand are not relaxed by testosterone, they relax with oxytocin but that arises in women in very different circumstances to how testosterone arises in men. It is important to understand how and when oxytocin arises in women. It arises from the activity of giving love, nurturing. And the inhibitor of oxytocin production is not enough time. But there is a lot more in this video than there is in my quick summary.