January 19, 2011

Lower-status females are more sensitive to signals that the mating season has begun

I can always tell when spring arrives because that's when nubile girls who are ovulating start pumping out their distinctive scent. Apparently only a small fraction of guys can detect this, in the same way that some people have super-sensitive tastebuds, and in the way that some people see colors well while others are color-blind.

It's even easier to tell because at '80s night there are perhaps 100 girls, all college-age, and if even a good fraction of them are ovulating, it knocks me over like a tidal wave when I'm walking up the stairs. However, last week I detected one girl in heat -- confirmed by her behavior in the dance cages -- even though it was still winter. Still, it had warmed up a fair amount since the dead-of-winter temperatures -- freezing, but not in the teens or 20s like it was before.

This made me realize that there must be differences between individual girls in how soon they come out from winter hibernation and get down to the business of looking for a mate and making babies. There's a trade-off: if she's highly sensitive, she will go into mating mode at even slight hints that the season has begun, so she'll never get a late start, although she'll occasionally come out too early (false alarm) and be left out in the cold. If she's hardly sensitive at all, she'll only come out when it's beyond a shadow of a doubt that mating season has begun, so she'll never be in mating mode too early and with little to do, but she'll occasionally remain in hibernation when she should be out and about.

There's no single best strategy to resolve this trade-off -- the more you try to eliminate one type of error, like the mistake of coming out too early and having little to do, you automatically suffer the other type of error, like sleeping in too late when there's plenty for you to be doing. So, a range of strategies will evolve and persist, rather than the single best strategy out-breeding all the others.

It follows as a prediction that females who are the most sexualized -- who lose their virginity earlier, have their first kid earlier, have more partners, have sex and kids outside of wedlock, etc. -- will be the early birds, while the least sexualized will be the stragglers. The most sexualized ones are really worried about sleeping through the party once mating season has begun, so they'll take the risk of going into mating mode too early. The least sexualized ones are more worried choosing the wrong partner, not having a great environment to conceive the baby in, and so on, from jumping the gun, so they'll take the risk of having their uteruses running idle when they could be put to good use.

And sure enough, that's just what we see. Here is a relevant WSJ article; skip to the chart at the very bottom. Mothers who give birth in January are the least likely to be married, the most likely to be teenagers, and the least educated, whereas mothers who give birth in May are the mirror image. Rewinding back to conception, that means the most sexualized mothers conceived in April, which leaves only 10 to 40 days after the beginning of spring for them to get into mating mode. The least sexualized mothers conceive in August, fully four months later -- talk about sleeping through the party! -- when there is no doubt left that mating season has begun and while the weather is still warm enough before the cooling of autumn.

This doesn't mean that the most sexualized mothers took only 10 to 40 days to find a stranger to mate with. They could have already been with someone for years. The point is even if they've been with someone that long, when during the year that they choose to have a kid do they go into baby-making mode? Damn early.

I wonder if colleges that have more lower-status students have earlier spring breaks than ones with more higher-status students?

2 comments:


  1. I can always tell when spring arrives because that's when nubile girls who are ovulating start pumping out their distinctive scent. Apparently only a small fraction of guys can detect this, in the same way that some people have super-sensitive taste buds, and in the way that some people see colors well while others are color-blind.


    That you have a very good sense of smell and also digestive problems is interesting. It is possible that severe allergic or immune system response can cause the sense of smell to become hypersensitive. A show I watched a long time ago had a kid that was "hyper-allergic". His mother said he could smell whether she had brushed her teeth or not when she checked to see if he was asleep for the night, from more than five feet away. Digestive problems like yours can cause large food particles to get into the blood stream, which would ramp up the allergic response of the body. On the other hand, I have allergies and my sense of smell is nearly gone. Maybe it goes one way or the other depending on the person.

    Anyway, I've decided to try about eight grams of glutamine a day to help my digestive problems. Mainstream science agrees that glutamine is used as a primary fuel/building block for the intestines themselves, so it should help there. Some people say it helps fix stomach ulcers. It's fairly cheap because the gym crowd uses it to try to enhance muscle growth. Also, it seems to be the primary component in several "digestive help" products. Glutamine is used as a fuel for the brain, so the Great Internet says you shouldn't take it before bedtime. The Great Internet also says you should take it before bedtime to help you sleep. That's very clear. If you have better information, then would you please tell me?

    The only sure problem is that if taken on an empty stomach, as suggested, then it will tend to increase water uptake in the large intestine. Reducing diarrhea or increasing constipation, depending on your digestive system.

    Do you think a strong immune system response, for any reason, would cause people's sense of smell to become greater? It makes sense that if body felt threatened by some substance(s) in the environment, that it would go to "high alert" and increase the sense of smell and maybe taste as well. Increasing the sense of smell would make it easier to detect and avoid the offending substance(s).

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  2. i gotta say i was somewhat skeptical of your claim of being able to smell fertility. i didn't think you were lying so much as embellishing the truth.

    but it looks like i was wrong and you really are able to tell. i still think you should amend your statment to "only a small fraction of guys can detect this consiously".

    http://www.nytimes.com/2011/02/22/science/22tier.html?src=me&ref=general

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