You've misconstrued Hamilton here. The thesis you attribute to Wallace was the one he favored. I'll be re-reading "Mate Choice Near or Far" later on tonight to make sure.

From memory though, the idea came out of his work on Red Queen dynamics -- if the purpose of sex is to rapidly churn out new recombinants in order to keep a step ahead of pathogens, then sexual selection should favor hard-to-fake signs of health as signifiers of genes that are currently "hot" for resistance to the commonest bugs. He did a study with Zuk that backed this idea up by correlating degree of "showiness" in male birds of various species with prevalence of blood parasites.

If you're looking at human behavior, you have to account for the fact that both men and women have an incentive to misrepresent how choosy they really are. Making a great show of finding fault with relatively-attractive-but-not-perfect members of the opposite sex is a standard way of trying to boost your own perceived choosiness and thus desirability. This distorts the picture.

What is "true attractiveness" supposed to be (as opposed to the supposedly untrue 1 to 10 ratings people give)? How would one measure such a thing?

it doesn't seem like a particularly interesting point to me. basically what you're saying is that people are more concerned with small differences in people they find attractive relative to people they find unattractive, dressed in mumbo jumbo that makes it sound more precise or scientific

You've misconstrued Hamilton here.

Google "parasite avoidance," and the last entry on the first page (from the book *The Bowerbirds*) says what I said. I'm not an expert on Hamilton -- maybe he didn't believe the theory deep down but just proposed it for investigation, or maybe only intended it for birds (as in the Hamilton & Zuk 1982 article).

What is "true attractiveness" supposed to be

Some objective measure of good looks. It sounds funny to say that there is attractiveness before perception, but maybe it's just a composite of health and symmetry. Something like that.

basically what you're saying is that people are more concerned with small differences in people they find attractive relative to people they find unattractive, dressed in mumbo jumbo that makes it sound more precise or scientific

The difference between a linear and log scale is not mumbo jumbo. It has real consequences too: you can't do ordinary arithmetic when the variable is measured on a log scale. Simple case -- taking the average. Any study that asks subjects to rate a person's attractiveness, and then takes the arithmetic mean of these ratings, is probably doing something wrong.

You'd need to transform these ratings so that they were on a linear scale first (ideally by finding out what base the log scale is on, and then exponentiating the ratings using that base).

In the future, if you don't know what you're talking about, don't comment.

Just based on personal observation, this makes sense to me (I apologize for stream of conciousness writing below).

This goes for many other things to: for example a "strong" radio station may be well over a million times stronger than a "weak" one, where as on a 1-10 scale "strong" may be rated as 8 or 9, and "weak" 2 or 3. A station rated as having strength of "5" may be 1,000 times stronger than the weak, but only 1/1000 as strong as the "strong" station. Of course for heavily geek populated groups like radio dx'ers, a logarithmic scale is already established...for example "strong" might mean ~90 dBu (w/"very strong" upwards of 110 dBu), medium ~60 dBu, weak ~30dBu.

The biggest factor I can think of here is that most people find it a lot easier to think in terms of linear, rather than logarithmic scales, even though i think most things in nature are best seen in terms of logarithmic scales. I guess that's why they call a*10^b notation "scientific" notation.

IQ is probably another thing best seen in logarithmic terms. By the way I believe the Gaussian distribution is designed for a logarithmized scale; this would make sense as something like height can't have a negative value, but log (height/avgheight) can, and indeed does about 50 percent of the time.

I think attractiveness is on a pretty smooth continuum. I also think the upperbound is pretty low. The most attractive kids at highschool weren't too different from the most popular faces you see in movies.

[Give me the best guys and girls from your highschool, Johnny Depp and Angelina Jolie, and some fresh judges, and then tell me some major path dependence isn't at play here.]

The reason I think you see more hair-splitting about 9s and 10s, etc, is because attractiveness isn't too objective after a certain point above the average. No men agree about the "hottest" celebrity because 10 is a myth. Endless subjective preferences make the 10.

[The most popular pornstars often look like transsexuals to me. The most popular fashion models look like adolescent males to Erik Holland. And Holland's "scientifically" attractive glamor models often look like inbred trailer skanks to me.]

I don't think any of those cross-cultural experiments or baby experiments, etc, would find any kind of uniformity in preference if we were just comparing pictures of, say, 9s and 10s. Perhaps even 7s, 8s, and above.

By the by, one study did find something like a nonadditive attractiveness (not in reported ratings, but in revealed ratings), but for males only:

"Overall, the relationship between outcomes and looks is similar for men and women. However, there is a surprising “superstar effect” for men. Men in the top five percent of ratings receive almost twice as many first contacts as the next five percent; for women, on the other hand, the analogous difference in outcomes is much smaller."

Fisher's theory sounds circular to me.

But if that were true for humans (and I'm only talking about us now), then we would finely slice up the attractiveness space near the ugly end, reflecting our worry of getting infected...

Above study aside, I think there is perhaps some evidence that this is how attractiveness is perceived.

Dean Hammermesh has three studies looking at wages, performance evaluation, and attractiveness, and in all three there were greater penalties for looking bad, than rewards for looking good.

So if we define attractiveness by revealed treatment instead of survey opinion, then the differences at the ugly end are more finely divided than the differences at the attractive end.

Fisher's theory sounds circular to me.

Google "sexy sons fisher" and you can get more detail. Basically, it's a peer pressure argument. In 1994, you may not have found baggy jeans attractive, but if you wanted to fit in, you had to wear them. In Fisher's view, if the potential mates of your offspring find X attractive, you'd do well to mate with someone who could give X to your offspring.

and in all three there were greater penalties for looking bad, than rewards for looking good.

That just follows from the perceived attractiveness scale being logarithmic: on the objective, linear scale, there are larger differences between perceived 1 and 2 than between perceived 9 and 10. So there should be greater penalties as you get uglier since the objective distance separating the tick-marks gets bigger and bigger.

So if we define attractiveness by revealed treatment instead of survey opinion, then the differences at the ugly end are more finely divided than the differences at the attractive end.

Again, they were measured on a subjective scale, so harsher treatment of uglies may simply mean that people respond to objective qualities (health, symmetry, etc.), in the same way that our visual system guides our behavior by responding to objective cues of distance (objects being fuzzier, closer together, etc. when farther away).

But perception tells us what was worth paying attention to: the near-term, the nearby, and the good-looking.

I don't need to Google, I have his collected papers right here and have actually read them -- just re-read and yep, I'm not crazy. When you find a secondary source attributing a dumb theory to a genius, it's a good idea to go check and see if that's what he actually said.

ok now, let's not degrade our within-blog asabiya! ;-)

For the log nature of 1 to 10 scales, check out the IMDB.com movie rankings by readers: a 6 is an OK run of the mill movie, 7 is pretty good, 8 is very good, a 9 only comes out once every few years.

The ratings are reasonable to within, say, 0.5: there's a pretty good chance you'd like a 6.7 more more than you'd like a 6.2.

Lots of data there to work with.

Another one of those academic urban legends, I guess.

For the log nature of 1 to 10 scales, check out the IMDB.com movie rankings by readers

That's another good example. Statisticians warn psychologists all the time about these subjective ratings (especially the ubiquitous Likert scales), since you can't take averages etc. etc. -- but they still do it anyway.

academic urban legends

To clarify, who originated the idea. The idea is out there, people discuss and test it, but they wrongly attribute it. My interest is always in the ideas themselves. Just don't make me anyone's biographer.

It sounds to me like this would be an easy thing to test. Any grad students out there looking for a research paper topic? Why not simply take a group of random people and have them rank pictures of others according to their perceived attractiveness? Then it'd be a simple matter to see which type of curve best fits the data. I'm sure you could also glean more hypothesizes from evaluating how the distribution changes from examining subsets of random people (i.e. all normal weight 19-22 year olds, etc), or how rankings of the same picture by the same person change based on pictures they've seen prior.

Fisher's theory sounds circular to me.

This is a good point; it is indeed a recursive process. But there are ways to "initialize" the self-reenforcement by arriving, by other means, at a weak sexiness for a given trait. The runaway sexual selection (AKA sexy son) mechanism might then amplify drastically both the trait and the tendency to find it sexually attractive.

How to initialize? One can use one of the other proposed mechanisms of sexiness and sexual selection - such as pre-existing sensory bias, Zahavi handicap, etc.

"academic urban legends"

Yeah, it's a misattribution of an idea of William Freeland's that Hamilton specifically argues against in the introduction to "Mate Choice Near or Far" in _Narrow Roads_. It's unlikely that the person who wrote the bowerbird book actually read the H&Z paper, since the blood parasites they used as an indicator of pathogen load for each species are only transmissible by mosquitoes.

This is interesting, I've actually thought about this problem before. I tend to also use a logarithmic sort of scale for ranking girls, and that seems to be the general method for most guys, but then I've also known guys who gave out 10s to almost any attractive girl - maybe they were reserving the fine detail for the lower end of the spectrum (perhaps that was the best they could get)?

On a side note, recently an acquaintance of mine was confused by an American TV show she saw (I live in China) where an ugly man was called a 3 by women and an attractive man an 8, and she had no idea what the numbers meant - evidently the 1 to 10 scale for attractiveness does not exist here.