Romantic involvement often reduces men's testosterone levels--but not always: the moderating role of extrapair sexual interest.

Testosterone (T) appears to facilitate what biologists refer to as mating effort--the investment of time and energy into same-sex competition and mate-seeking behavior. Multiple studies show that men who are romantically involved (i.e.

Salivary testosterone and body composition among Ariaal males.

To determine if testosterone is negatively related to acute and/or chronic nutritional status among men in a subsistence society, saliva samples and anthropometric measures were compared among nomadic and settled Ariaal pastoralists of northern Kenya. Fifty-six nomadic men and 62 settled men facing drought conditions, estimated ages 22-96 years, were sampled. Measures included height, weight, four skinfolds, and %body fat by bioelectric impedance (BIA).

Ovarian function in the latter half of the reproductive lifespan.

The relationship of age to four aspects of ovarian function was investigated: daily progesterone levels, pulsatile progesterone secretion, follicular and luteal estradiol levels, and preovulatory estradiol levels. Daily progesterone levels decrease after age 40. Pulsatile progesterone secretion remains approximately stable with age, though older women have somewhat higher late luteal activity.