When in college there was this girl at my church who had a crush on me (or at least she acted like she did). I had my own dorm room and I am sure I could've...um...taken advantage of the situation. We dated for a few months, but I broke it off the day after Xmas that year.
The thing was she had a distinctive scent that just turned me off. It wasn't that she stunk or didn't have good hygeine; I just wasn't that much attracted to her even though she was physically attractive. At the time, I chalked it up to my religious ethics of not taking advantage of someone for whom I had no feelings, yet the "smell factor" has always...er...lingered in my olfact...,no, mind. What catches my attention about this abstract is that the MHC pushes animals towards heterozygosity or heterogeny. Keeping the appropriate amount of genetic (allelic) variation within populations is crucial for the survival of that group. In addition to avoiding the weakness and defects found in inbred, homozygous individuals within a group, it provides sufficient mutant or more-varied strains at either end of the population distribution that aids in survival from selective pressures presented by conditions. Also, I think we are often influenced in our choices in life by unseen forces. No, not the divine, but rather biological pressures that we are mundanely unaware of and that we attribute to our conscious deliberation or thought. Still, we must go through life thinking we are in control even though the currents around us determine our course more than our visible compass. Preston ----- Original Message ----- From: CrossBow To: Memphis Freethought Alliance Sent: Friday, December 05, 2008 10:26 AM Subject: Major Histocompatibility Complex Alleles, Sexual Responsivity, and Unfaithfulness in Romantic Couples That "Smell Factor" again... Major Histocompatibility Complex Alleles, Sexual Responsivity, and Unfaithfulness in Romantic Couples Copyright Copyright © 2006 Association for Psychological Science ABSTRACT ABSTRACT—Preferences for mates that possess genes dissimilar to one's own at the major histocompatibility complex (MHC), a polymorphic group of loci associated with the immune system, have been found in mice, birds, fish, and humans. These preferences may help individuals choose genetically compatible mates and may adaptively function to prevent inbreeding or to increase heterozygosity and thereby immunocompetence of offspring. MHC-dissimilar mate preferences may influence the psychology of sexual attraction. We investigated whether MHC similarity among romantically involved couples (N= 48) predicted aspects of their sexual relationship. All women in our sample normally ovulated, and alleles at three MHC loci were typed for each person. As the proportion of MHC alleles couples shared increased, women's sexual responsivity to their partners decreased, their number of extrapair sexual partners increased, and their attraction to men other than their primary partners increased, particularly during the fertile phase of their cycles. and... Birth Control Pills Affect Women's Taste in Men How synthetic hormones change desire in women--and their choice in a mate By Melinda Wenner This year 2.25 million Americans will get married—and a million will get divorced. Could birth control be to blame for some of these breakups? Recent research suggests that the contraceptive pill—which prevents women from ovulating by fooling their body into believing it is pregnant—could affect which types of men women desire. Going on or off the pill during a relationship, therefore, may tempt a woman away from her man. It's all about scent. Hidden in a man's smell are clues about his major histocompatibility complex (MHC) genes, which play an important role in immune system surveillance. Studies suggest that females prefer the scent of males whose MHC genes differ from their own, a preference that has probably evolved because it helps offspring survive: couples with different MHC genes are less likely to be related to each other than couples with similar genes are, and their children are born with more varied MHC profiles and thus more robust immune systems. A study published in August in the Proceedings of the Royal Society B, however, suggests that women on the pill undergo a shift in preference toward men who share similar MHC genes. The female subjects were more likely to rate these genetically similar men's scents (via a T-shirt the men had worn for two nights) as pleasant and desirable after they went on the pill as compared with before. Although no one knows why the pill affects attraction, some scientists believe that pregnancy—or in this case, the hormonal changes that mimic pregnancy—draws women toward nurturing relatives. Women who start or stop taking the pill, then, may be in for some relationship problems. A study published last year in Psychological Science found that women paired with MHC-similar men are less sexually satisfied and more likely to cheat on their partners than women paired with MHC-dissimilar men. So a woman on the pill, for example, might be more likely to start dating a MHC-similar man, but he could ultimately leave her less sexually satisfied. Then if she goes off the pill during the relationship, the accompanying hormonal changes will draw her even more strongly toward more MHC-dissimilar men. These immune genes may have a "powerful effect in terms of how well relationships are cemented," says University of Liverpool psychologist Craig Roberts, co-author of the August paper. Note: This article was originally published with the title, "A Tough Pill to Swallow". -- gnothe se auton --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Memphis Freethought Alliance" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/memphisfreethoughtalliance?hl=en -~----------~----~----~----~------~----~------~--~---
