Testosterone decline, future time bomb?
It is easy to find explanations for the decrease of testosterone.
Married men who have grown 10 years older will surely also be more passive and sitting more. The pressure from the traditional chair on the vessels going to the genitals is very damaging, and sitting (probably with a slightly heavier upper body) also raises the body temperature four degrees above the physiological optimum, and also above the temperature when standing.
The solution would be a two-part swinging saddle chair and loose and cool clothing. Being without underwear would be a very good factor in decreasing the temperature and enhancing the flows.
In addition to age, also hormone disturbers decrease testosterone. These (including antiseptic home cleaners) are likely to be used more in the family because women clean more than men and also want more "spotless" surfaces.
Testosterone is becoming a question of destiny for mankind. There is an increasing number of young men in the industrialized countries, who also have so low testosterone levels that they cannot get erections, but also they are not interested in girls.
In Japan these men are called "grass-eaters". When nothing better is available they are dating a flirtatious doll-like virtual girlfriend in their cellphone.
Testosterone health is rapidly deteriorating, which is already really threatening to the global birth rates, not to mention joyful sex.