Evolutionary psychologists and anthropologists have, for years, theorized the evolutionary, and often by association genetic, components of complex social sexual behaviors. From the function of the female orgasm to why we fall in love , researchers have looped theory around theory to connect what we do sexually with overall theories of natural selection and evolutionary adaptation.
While these theories often make for interesting dinner conversation (for example, one early evolutionary explanation for female orgasm was that its function was to ensure a woman would like down after intercourse, and thus increase the chances of conception) they are, by their very nature, impossible to ever prove or disprove.
As sciences ability to study human DNA, and map the entire human genome has progressed, so to has researcher’s interest in looking at how our sexuality may be determined by our genes.
One of the early examples of studying genetic components of sexuality is the much publicized search for a gay gene.
Researchers at Ben Gurion University and the Hebrew University of Jerusalem have greatly broadened the scope of this kind of research, with a paper released on line in the journal Molecular Psychiatry entitled "Polymorphisms in the dopamine D4 receptor gene (DRD4) contribute to individual differences in human sexual behavior: desire, arousal and sexual function".
The paper compared the responses to on line questionnaires about sexual desire, arousal, and function with the DNA of 148 male and female university students. The researchers focused on a gene called the "dopamine D4 receptor gene (DRD4)" which has been shown to be involved in erection capacity in male rats.
They found an association between variants in the gene and the self-reports of sexual arousal, desire, and function. Specifically they found that certain variations are correlated with a depressing effect on sexual arousal, desire, and function, while other variations are associated with an increase in sexual arousal.
The specific meanings of these associations, and the strength of them, seem impossible to quantify in any meaningful way given that this is the first time researchers have reported on this in humans. To further make meaning difficult to determine, it doesn't appear as if their questionnaires on function and desire were in any way validated (they used a validated, but old, arousal inventory). So their measurements of function and desire need to be taken with a larger-than-DNA sized grain of salt.
But the importance of this research can’t be denied, and it comes with heady possibilities and equally serious concerns.
