OK, this study purports to show that (some) men make stupid decisions when there are pretty women around. Nothing too wildly controversial so far. It then goes on to suggest that the phenomenon is correlated to testosterone levels, ok.
Now the question :
Is this at all possible ? Testosterone levels fluctuate - at what point would they influence finger growth ? Is it a sort of ‘average over time’ idea ? Does the same apply to women ? Is it a joke ?
I know what everybody’s going to be talking about at my dinner party.
I’ve done a lot of reading about hormones and testosterone in particular and there is no doubt that testosterone is tricky stuff. “Normal” total testosterone levels range from 200 to 800 ng/dL so there is a huge variation, but there is no way to relate that to body type. Sometimes even naturally muscular guys are normally in the low end of the range. Correlating testosterone levels to relative finger lengths sounds like chirognomy to me. One also wonders if they are talking about total testosterone or free testosterone. Most of the testosterone in your body is bound to SHBG and albumin and isn’t available to testosterone receptors. It is possible to have low total testosterone but high free testosterone and vice versa.
You’re right to say that testosterone levels change. They change from hour to hour during the day and they change from year to year. What most people don’t know is that just as importantly, the number of testosterone receptors can also change. Testosterone is useless unless it has a receptor to bind to. Like I said, testosterone is tricky stuff and so any claim like this finger length business would need some very hard science behind it before I would believe it.
I doubt that anyone’s suggesting that testosterone causes finger growth, but rather that the same cause of finger length differences causes higher testosterone.
Surely you’re not saying that a normal person would suffer that huge a variance in testosterone levels! I expect that people suffer variations within a range that is normal for them rather than the range that is normal for all men.
Studies have shown that lesbians have finger length proportions See here. more similar to those of men than of women.
Yes, the difference in finger lengths is due to exposure to testosterone during fetal bone growth in the womb-- ie, when the patter for finger length is set. It’s hypothesized that more testosterone = bigger difference in the length of the ring vs index fingers, and also that the same difference in testosterone levels affects brain development, and hence certain personality tendencies (aggressiveness, competitiveness, etc.).
It could be measurement error on your part, but keep in mind that there is always going to be variation between individuals, and there are bound to be other things that can influence finger length. Biology isn’t destiny, and it’s a mistake to think that these sorts of things work like physical laws.
*Surely you’re not saying that a normal person would suffer that huge a variance in testosterone levels! *
No, I’m not saying that.
I expect that people suffer variations within a range that is normal for them rather than the range that is normal for all men.
Exactly right. The point is that it is difficult to make generalizations about a parameter that can vary by 400% and still be “normal.”
It’s talking about prenatal hormonal influences.
They are saying that relative finger length tells them which men have higher levels as adults. I don’t deny that hormone levels in the womb affect growth. I’m just asking to see the study that relates adult finger length to adult testosterone levels.
I had my blood tested four months ago and my testosterone was 407 ng/dL which is below the midpoint for “normal.”
Here is a picture of my hand taken just now. Clearly, my ring finger is longer than my index finger so they would classify me as having “high” testosterone. One data point doesn’t make a study, but it definitely makes me question their ideas about finger length and testosterone levels. I have a valid reason to doubt them and it will take more than logic to convince me they are right. Let’s see the data.
I think that the ring finger is longer than the index finger in most men (who, despite variation, almost all have higher testosterone levels than almost all women). So just the fact that it’s longer wouldn’t be enough to classify a man as having high (for a man) testosterone levels. Presumably, they were judging by the ratio of lengths, with ratios above some value corresponding to “high” testosterone.
How are you supposed to measure? Looking at the palm side of my hand, the lengths are almost indistinguishable; from the back side, my ring finger appears clearly longer.
Look at the palm side and measure from the crease where your finger joins with the hand. Ideally, you want to measure the bones-- ie, the 3 phalanges that make up your finger. Even in men, the delta isn’t that big, so you have to measure very carefully. I think that a 4-5 mm difference would be considered quite large.
My point was that on my right hand, the ring finger is about 1/2 inch longer than the index finger; and on my left hand they’re equal (the ring finger’s a little shorter and the index a little longer). And I happen to know that I have a fairly high testosterone level.
So this means I’m a high-testosterone male with lesbian tendencies on the left side only?
Maybe it means that your left hand doesn’t know what your right hand is doing.
I wouldn’t overanalyze this. There could be any number of reasons why individuals will vary in this trait, and hormone levels can’t be the only thing that influence finger length. But even if hormones were the dominant factor in determining finger length in most people, that would still only be “most people”.
For a fairly interesting article on the differences in body size/shape between men and women, see this link here (which cites sources from the Army and others). There’s a small mention of finger/hand size differences overall.
NOT WORK-SAFE, has pictures of nude women and nude transsexual women.
There are still some mysteries about how different hormones influence body growth and development, as well as a continued argument over what makes a male mind a male mind, and a female mind a female mind, etc. Some look for evidence that if a body type falls outside of established norms for the subject’s birth sex, then it could mean either a hormonal irregularity which may or may not warrant correction. Transsexual persons and researchers who are trying to develop conclusive proof that transsexualism is an actual physical condition, and not a mental illness, look very hard at studies of how hormones influence skeletal, muscular, and other development to see if there are correlations between body shape and development and people who are diagnosed as being TS/TG/Gender Dysphoric/etc. Obviously one must look within a specific racial/ethnic background group - comparing people of Thailand with people of Sweden is likely to yield insane results.
There was a segment on one of the PBS science shows about this. Researcher looked at photo copies of the hands of 6 sprinters who he had never seen, nor had they ever run against each other. He then picked the outcome. He called the first and last two correctly, and transposed the middle pair. Seems there might well be something to this.
