Prairie Voles, early stress and sexual behavior

Not going to start where the title suggests. First, I want to highlight another quote from the Carol Tavris article Mind Games. David Blakeslee noted this in a comment recently and it is an appropriate beginning for this post:

The scientific method is designed to help investigators overcome the most entrenched human cognitive habit: the confirmation bias, the tendency to notice and remember evidence that confirms our beliefs or decisions, and to ignore, dismiss, or forget evidence that is discrepant. That’s why we are all inclined to stick to a hypothesis we believe in. Science is one way of forcing us, kicking and screaming if necessary, to modify our views.

Live by the sword…
It is no secret that I believe research does not support a reparative drive formulation as a general theory for same-sex attraction. On the other hand, I need to practice what I preach about confirmation bias so I am looking for any evidence that could support the notion. As a consequence, I am reviewing the literature in the area of hormones, early brain organization, attachment and sexual behavior. A 2003 article by C. Sue Carter, using prairie voles as a model, reported the following:

Another example of the consequences of perinatal exposure to stress hormones comes from work with prairie voles; in this species, corticosterone treatment during the perinatal period altered both social and reproductive behaviors. In female prairie voles, postnatal treatment with corticosterone was associated with an increased preference for unfamiliar partners versus siblings, lower levels of alloparenting and increased masculinization of sexual behavior (indexed by mounting behavior in females). A more stressful early life, including possibly the absence of the father, also inhibited alloparenting in female prairie voles from a population captured in Illinois [92–94]. In nature, a lack of preference familiar animals or unwillingess to engage in alloparenting behavior might be associated with less tendency to remain with the natal family, further undermining communal breeding and monogamous social systems [20].

Note that stress hormones introduced around the time of birth effected adult parenting and sexual behavior, including same-sex behavior in females. This is the kind of evidence one would need to make a link between high levels of stress and later sexual behavior. There is nothing here that provides direct support for the developmental scheme of reparative drive theory. However, the notion that attachment stress might act to organize the developing brain structures involved in sexual behavior is plausible. Several lines of research suggest that hormones at critical periods may impact sexual behavior. However, what human experiences would lead to comparable hormone changes is not at all clear. We know that many people experience neglect, abuse, disappointment, etc., during early development and demonstrate no same-sex sexual interest. Individual genetics may play a role as may cognitive mediation and the individual experiences which shape self awareness.
One thing is clear. Whatever shapes sexual attraction leads to clear brain responses out of the awareness of the person. What is in awareness is most often experienced as intrinsic. As opposed to prairie voles, however, what we do is mediated by cognitive and social concerns that often are of greater importance than impulse.