Changes in Male Sexual Preference
Changes in male sexual preference also seem to follow the "practical" male reproductive years, and may indicate a testosterone link. The data is shown in the graph below.
Males Indicating Changes in Sexual Preference by Current Sexual Preference and Age Cohort (M=Male) (H=Heterosexual, B=Bisexual, HO=Homosexual, NS=Ambiguous, AS=Asexual)Changes in male sexual preference favor the switch to both heterosexuality and bisexuality in both the Under-25 and 25-34 age cohorts. In the 35-49 age cohort, in which males experience substantial testosterone depletion, bisexuality passes heterosexuality as the primary target of sexual preference change. This trend increases sharply in the 50+ cohort, again suspiciously implicating a testosterone link in male (and possibly female) sexual preference changes. Homosexuality, as a target of sexual preference change, is also elevated during the testosterone-depleting years.
Discussion
The most distinctive pattern of age and its relationship to sexuality comes from the Under-25 females. What are we to make of their high rates of reported bisexuality? Testosterone levels are elevated in the Under-25 females, but sexual orientation is a complex neurophysiological process, and testosterone is merely one of the players in this neurochemical zoo. We must also note that the Under-25 females, while expressing the lowest tendency towards heterosexuality, also report lower copulation frequencies than the reproductive 25-34 cohort.
The fact that the Under-25 females seem to be expressing greater preference for bisexuality may be indicative of the fact that high testosterone levels in females correlate with non-heterosexual behavior, which is implicated by a number of other studies. An age-related testosterone (and possibly estrogen) depletion model in females seems to correlate pretty well with the decline in bisexual and homosexual behavior over time. However, an undisputed model of human sexuality is probably decades away.
Testosterone depletion does not seem to be as active in male sexual preference changes, but as males age, our results indicate that if their sexual preference changes, they are more likely to favor non-heterosexuality. We also note a slight elevation in reported male bisexuality in the younger age cohorts, which obviously contradicts a linear testosterone model. However, the current research on human sexual orientation implicates a complex time-dependent and non-linear relationship between testosterone levels and sexual preference. For example, very high testosterone levels may also result in non-heterosexuality, which may contribute to the elevation in reported bisexuality in the Under-25 and 25-34 cohorts.
We also cannot discount the apparent influence of offspring on sexual preference. The movement towards heterosexuality that occurs in the 25-34 and 35-49 age cohorts may also be stimulated by an "offspring effect", which would presumably promote conventional sexual practices as people conform their behavior within their social groups to promote child-rearing.
With the exception of the under-25 females, the Conservatives present a consistently heterosexual face, which stands quite apart from the other political cohorts. While Conservatives are more likely to use social cues in behavioral self-regulation, our cognitive results are consistent with the fact that there indeed may be biological differences in sexual orientation, on average, between Conservatives and Liberals.
In particular, it is possible that the testosterone-estrogen ratio is higher for Conservative males than for Liberal males, and conversely, the testosterone-estrogen ratio may be greater for Liberal females than for Conservative females. While this is consistent with the cognitive evidence, it remains to be seen.
We must also consider the impact of sexual preference on political attitudes, as non-heterosexuals are more likely to benefit from the more permissive Liberal political agendas than the Conservative. We will pick up this discussion in our next installment, as we go over some very interesting correlations between sexual preference, the left brain, the right brain, introversion (an indicator of elevated prefrontal cortical activity), and extroversion (an indicator of elevated temporal cortical activity), along with the curious possibility of a rebirth of heterosexuality in the born-again Christian males.
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Brack and Zhang, October 2006
Email: Brack@neuropolitics.org
Zhang@neuropolitics.org
