Infidelity... genetic, social?

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http://news.bbc.co.uk/1/hi/health/3783031.stm

Professor Tim Spector of St Thomas Hospital in London claims that there is a gene responsible, at least partly, for infidelity. He doesn't go so far as to blame the gene for cheating on partners, but during his research of twins he discovered that if one twin has betrayed, the chance for the other is more or less 55%.

Of course, twins share quite a lot of genes and there are many characteristics of a person that may contribute to that person choosing cheating over faithfulness at some point. The Professor doesn't believe in any single gene immediately responsible for infidelity:

He concluded that genes play some role, although it actually comes down to social factors.

Dr Petra Boynton claims, however, that social factors are crucial, especially in early development:

As I see it, in so far as genes affect a person's personality, they simply have to affect predisposition to fidelity or infidelity, indirectly, by affecting factors that are more immediately involved in the final outcome.

However, the control of brain over the rest of the body is sufficient for a healthy human to decide against infidelity at a given moment and turn down the opportunity to betray his or her partner. Ultimately, there is no absolute compulsion and it comes down to making a choice.

Children copying the parents' patterns seems more convincing. The idea of doing whatever you can get away with also seems quite matching, especially if we consider notorious cheating connected with general negligence and/or abuse.

In the same article, they mention that 23% women are not faithful and suggest that it may be related to seeking better genetic material. That would mean that when a woman meets a man whom she estimates to have a better set of genes than her partner, she is pressured to unfaithfulness.

However, I can't agree with that. At least not in any absolute sense. As I have said, there is a limit to the control biological drives have over human decision and an everage healthy human is able to resist temptation if he or she bothers. Also, better estimated genetic material may be a sufficient explanation for leaving the current partner and moving to the better set of genes, but not for cheating. To have that sort of influence, sexual drive would have to be an abosolute compulsive force, which it isn't.

23% seems high to me... In several other sources, I read it was 16% for women and 15% for men. Well, perhaps the 15-16% estimation only counted regular and frequent cheating as cheating... I don't know.

Another article also at BBC deals more closely with the statistics:

They move so far as to claim that one in ten children is being brought up by a man who is unaware that he isn't the real father.

As an explanation, they suggest that during ovulation, a woman's sexual preferences change and she is attracted to a different sort of men. While the steady partner may be the best person to provide a safe house for the children, another man may have better genes, meaning stronger and healthier children. This would be related to testosterone level. A man with less testosterone would be more fitting for the role of a steady partner, while one with more testosterone would be more attractive as a potential biological father of the children, supplying healthier and better genes.

In the case of Mr Wise, on which the article is based, it proved that he fathered none of his three children after tests for a rare genetic ilness requiring both parents to carry the defect showed that he didn't carry the defect and therefore he couldn't be the real father. Further DNA testing proved that and it ultimately came to daylight that none of the children had Mr Wise as the biological father.

Additional read:

http://news.bbc.co.uk/1/hi/sci/tech/179988.stm

http://news.bbc.co.uk/1/hi/sci/tech/701286.stm

[ June 30, 2004, 16:51: Message edited by: chevalier ]

 

Well Chev, we normally don't agree, but I do agree with you on this one. That regardless of powerful biological drives that urge us to be unfaithful, that it is ultimately a conscious decision one makes. I say that both in the case of males and females.

As far as the statistics go, 23% really doesn't seem that high, but I may be more cynical than you. One would expect that the number of men cheating on their partner would be approximately the same as the number of women cheating on their partner. The only way this would not be true is if one sex tended to take multiple partners far more than the other sex. While I do not doubt that cheating with multiple partners occurs, I see no reason why men would tend to take multiple partners more than women.

What all this gets back to is that many people feel than men are more likely to cheat on their partners than women are, and it just doesn't seem that likely to me. Unless, for some reason, in most of these moments of infedility the man is married, and the woman is not. Again, I find this unlikely. I don't know if that information is out there. It seems like the statistics you provide are not specific to make such a determination.

For example, if a married man has sex with an unmarried woman (so obviously not his wife), the man is obviously being unfaithful, and would be included in the 15% of unfaithful males. Is the woman also considered unfaithful in this regard? Or would they only both count if they were both married to other people?

 

I think Joacqin (I guess he was it, I may of course err) posted a link in the "boys suck" thread a year ago, that points out the same.

My view, cheating is bad. It is just not fair to the other one. If you say you'le be true, you better should be true.

But my observation is, that women tend to be more unfaithful then man. That ofcourse is only anecdotical (sp ?). But it would make sense that a women is harder treated reputation wise then men when caught. The reason women get so much fire for changing parnters is... they are likely to do so... ?

[ June 30, 2004, 17:52: Message edited by: Iago ]

 

Hey, we're only humans, and humans happen to lie and cheat on a daily basis. I know someone, who has grown so accustomed to lying and twisting his facts, that he doesn't even notice he's doing it anymore. Of course not everyone is as bad as this particular guy, but lying is part of human nature, and cheating is too in a way. Humans aren't monogomous creatures to begin with, and we're also the only species that have sex for other purposes than to reproduce ourselves.

Personally i don't make a big issue out of it, it's how the world turns. I've told a lie when it suited me best, and i've been lied to occasionally. I've cheated on several girlfriends, and some of them cheated on me. That's the way things work i suppose.

 

That article is no real surprise. People are a product of genes molded by an environment. Essentially every trait you define will be
heritable to some degree. It has been shown through twin studies that even religiousity is heritable. That's not to say that there is a "religiousity gene," but it turns out that people with similar biological makeups tend to have more similar personalities, and, in turn, a greater chance to become religious.

Humans are an interesting case when it comes to mating systems. Although we may define ourselves as a monogamous that is not really the case. Our biology indicates a slightly polygynous mating system. Namely, our species is sexually dimorphic in size, which is indicative of male-male competition for females (which, in turn, implies polygyny). Furthermore, male testes size is moderate in size relative to other primates - indicating that in our evolutionary history promiscuity was prevalent enough for sperm competition to be a relevant selective force.

From an evolutionary standpoint, infidelity is pretty easy to understand. Unfaithful men probably had reproductive advantages over faithful men thereby allowing more of their genes into the next generation (which explains why such behavior exists even today). Women also benefit from infidelity (evolutionary speaking). When a women engages in extra-pair copulations, she can often confuse paternity, thereby illiciting more material resources from different males thinking they are the father. And, as one might intuit, there is a postive correlation between resources (i.e. food) and reproductive success.

 

Woo Hoo! Infidelity!

OK, I suppose that needs some explanation.

I am adopted, and while I don't know the circumstances surrounding my conception, it is entirely possible that some form of infidelity was involved. So SP might have some sinners to thank (blame?) for my being here!

OK, kidding aside, infidelity is something I would never consider. If I stopped caring for my wife enough to have it go that far, I would get divorced first (not that this is ever likely to happen).

 

while no doubt biology and social environment / experience do contribute, i have to agree that at the end of the day, we all make choices about our behaviour - in all sorts of areas, not just this on.

my partner has always been clear that infidelity is unforgivable, and would lead to the end of our relationship. i value this, and so (despite occasionally being tempted by eye candy) chose to remain monogamous. for me, it isn't worth what i'd be risking.

btw i've heard the stat that one in six people are mistaken about the identity of one or more of their parents. certainly, our university stopped students doing a basic cheek cell test for blood grouping as part of first year science / med / dentistry because too many people got awkward results.......