I tried to post the following at the designed place; it would not work.
Here is my comment on this:

"I suggest you have found that DHEA is important in longevity.  After a
woman gives birth, her DHEA declines for a number of years.  Hence, the
first birth is exposed to increased maternal DHEA, a situation which I
suggest is best when maternal DHEA is plentiful.  This may be involved in
the effects of being "first born."

I also suggest testosterone exerts negative effects on availability of
DHEA.  Therefore, females will have a greater supply of DHEA per life span
than males.  Based on the foregoing paragraph, as each son is born the
"ratio of testosterone to DHEA exposure in utero" increases; this will
cause a decline in life span.  However, also based on the foregoing
paragraph, with age the mother again increases DHEA production which
produces a more favorable "ratio of testosterone to DHEA exposure in utero"
after many births.

It is known that rural populations represent populations of lower
testosterone compared to urban populations.  Therefore, the positive effect
of "farm" life on longevity may also be due to reduced testosterone.
"Western" life may also represent a population of reduced testosterone."

James Michael Howard
Fayetteville, Arkansas