Nerve Growth Factor and “early stage romantic love,” DHEA and Testosterone
James Michael Howard,
Based on the new finding that nerve growth factor
increases in "early stage romantic love" then dissipates within a
year (Psychoneuroendocrinology 2005;
Emanuele, et al.), I suggest the
"When we experience things new, we produce a stress response. This produces the DHEA to cortisol ratio. If the experience produces more DHEA than cortisol, this produces "good" responses; if cortisol is too high, this is a "bad" response.
DHEA increases nerve growth factor; cortisol reduces it. One falls in love with another who increases their DHEA to cortisol response. As the "newness" dissipates, the effects of growth caused by DHEA and NGF also dissipates. If the original, and subsequent, effects are strong enough, a "bond" is formed by growth caused by DHEA and NGF."
Testosterone is paramount in “early stage romantic love.” Testosterone has been demonstrated to be involved in male facial attractiveness and coitus activity in women (see articles at http://members.cox.net/jmhoward3/evolution.html ). Testosterone reduces DHEA levels but also increases nerve growth factor. That is, increased testosterone probably increases the NGF response to “early stage romantic love,” but also may cause a more rapid decline in the stress response elicited by male and female interactions. Therefore, this explanation may also explain why men stray faster than women. However, my work also suggests that the "secular trend," the increase in size and earlier puberty of children, is caused by an increase in the percentage of individuals of higher testosterone with time within the population. This is primarily driven by women of higher testosterone. Therefore, women are becoming more and more like men and this will shorten the time between "early stage romantic love"s stimulation of NGF and its dissipation in men and women.