Thread: Beauty and Evolution

unattractive people have children, too. there's genetic variation as well.

Why would we desire attractive traits if they didn't have an evolutionary advantage? Attractive people's genomes have a greater chance of being passed on.

Originally Posted by Xei

Why would we desire attractive traits if they didn't have an evolutionary advantage? Attractive people's genomes have a greater chance of being passed on.

I think you just answered your own question.

Attraction can be a measure of how viable a person's genes are and therefore how likely they are to pass on beneficial traits. We find attractiveness in a sense of order, this is why symmetrical faces tend to be more attractive. Disorder in genes makes genes less viable and higher risk. Disorder in attractiveness is directly linked to disorder in genes. Order in attrativeness is directly linked to order in genes.

This is only my speculative hypothesis.

You've described the question in more detail, but you haven't answered it. Why have we not evolved to have less disorder, if that's the case?

Because evolution isn't flawless. Its like you're asking "Why aren't we perfect?"

No that doesn't work either, like I said, attractiveness is heritable. An attractive man and an attractive woman will tend to have an attractive child. It's a trait like any other but it is not acted on by natural selection like other traits. Why is beauty different?

How is it not acted on by natural selection?

Attractive people have good genes.
One person finds another attractive.
Their offspring has good genes and is attractive.

Non-Attractive people do not have good genes.
One person finds another repulsive.
No offspring, no bad genes are passed on.

If you're asking "If this is the case, why are their ugly people?" There are many reasons. We as humans are able to consciously oppose natural selection to a degree. Ugly people can choose to mate. As well, we have a massive number of people, making the definition of Attractiveness these days very wide. Finally, again with a massive number of people, due to the fact that evolution is not perfect, 2 Attractive people can have an unattractive child.

How is it not acted on by natural selection?

Attractive people have good genes.
One person finds another attractive.
Their offspring has good genes and is attractive.

Non-Attractive people do not have good genes.
One person finds another repulsive.
No offspring, no bad genes are passed on.

Yesss that's the basic mechanism of evolution by natural selection...

If you're asking "If this is the case, why are their ugly people?"

Well exactly. That was the question.

There are many reasons. We as humans are able to consciously oppose natural selection to a degree. Ugly people can choose to mate. As well, we have a massive number of people, making the definition of Attractiveness these days very wide. Finally, again with a massive number of people, due to the fact that evolution is not perfect, 2 Attractive people can have an unattractive child.

This simply isn't how evolutionary theory works. If there is a selection pressure it should effect a change. It doesn't need to be 'if you have this trait you won't have children and if you do you will'. That's ridiculously oversimplified.

The large population nowadays is pretty much irrelevant considering the timescale of evolution, and anyway, the worldwide population doesn't affect an individual. Attractiveness is actually a very unambiguous trait. Virtually everybody agrees on what is attractive.

I don't know what 'evolution isn't perfect' is supposed to mean really. The frequency of unattractive genes should decrease, simple as.

Physical appearance is the product of more things than just genes. Environment in the womb during development influences it a lot, for example. I remember reading that face symmetries (and this influences attractiveness a lot) is particularly sensitive to exposure to toxins during pregnancy.

Second, people are largely monogamous. That is, ugly people mate with ugly people and usually reproduce at the same rate as attractive people.

Third, attractive people can have ugly children. It's basically the same thing with genetic diseases. They will always be present in the gene pool, even if they kill the individuals (and you can't get more deleterious than that)

Fourth, even if the average attractiveness of the population was increasing due to sexual selection, you wouldn't notice it because you wouldn't find your average individual attractive. You would only be attracted to the above-average attractive individuals.
However, I don't think it changes a lot: on average, 10s mate with 10s and produce children that are 10. 1s mate with 1s and produce children that are 1s. You always end up with similar proportions of (un)attractive people.

Fifth, what we find attractive is largely culturally determined and changes over time.

A) What's attractive can strongly be influenced by culture, and on a timescale far too rapid for evolution.

B) There are other factors at work. An attractive woman might herself be attracted to a plain man due to his intellect, for example. Intellect of course clearly has been attractive throughout the course of human history given it's evolution. I'd speculate that the reason why we're not all amazingly intelligent is because less intelligent people tend to have more children, thus weakening selection pressure.

C) Who says this isn't happening on the grand scale, it's just taking a long time to occur? As an example, we lack a lot of body hair compared to our ape cousins (even if our hair follicles are actually more numerous), something which is generally considered to be more attractive.

D) People are attracted to different things, which overall weakens any selection pressure that may exist. In the Western world people are generally attracted to slim figures but there are those who prefer large people, for instance.

These are my suggestions:
1) Attractive people can have unattractive children
2) People settle
3) Physical appearance isn't the only criteria
4) The standard for what is attractive changes

Though general attraction may come as the result of our genes, what we're
attracted to specifically may be influenced by environmental factors. That way,
all genes are tested so that no potentially good ones on an "ugly" person go
untried, so to speak. It is beneficial to the survival of a species to work this way.

What you are ignoring is the factor of relative attractiveness. People tend to be attracted (and therefore mate with) people who are of a relative attractiveness to themselves. It is unusual for a very attractive person to be matched up with a very unattractive person. In order for attractiveness to be a dominant trait, everyone would have to be seeking out a mate that is more attractive than themselves, which is impossible.

Either people have to match up with someone equally as attractive as themselves, which produces just as many unattractive offspring as attractive ones since the relatively unattractive pairs are still mating, or a more attractive person mates with a less attractive one and their offspring tend to be more average. Either way, you end up with a population that averages out to mediocre no matter how many generations are produced.

This of course only applies to our societal norm of paired mating. If we were in more of a pack social structure in which only the most desirable members mate at all, then you would see a tendency towards more attractiveness.

First and foremost this is as subjective as it gets. The only thing to understand is essentially this. "Beauty is in the eye of the beholder" No one is asking the most simple and fundamental question that needs to be asked. To the OP, what is considered attractiveness in this discussion? Someone brought up "good genes" being passed on. What are considered "good genes?"

Originally Posted by ShadowNightWing

First and foremost this is as subjective as it gets. The only thing to understand is essentially this. "Beauty is in the eye of the beholder" No one is asking the most simple and fundamental question that needs to be asked. To the OP, what is considered attractiveness in this discussion? Someone brought up "good genes" being passed on. What are considered "good genes?"

Although I do agree with your point about good genes, since there really is no such thing, there have been studies done showing that beauty is somewhat universal; I remember a particular one in which pictures were shown to infants and their reactions were gauged and judged to be more positive towards the same people. Things that are more symmetrical are generally more pleasing to the eye.

The good genes thing is a good point. The only "good genes" are the ones that persist.

To the other posters, facial attractiveness is not arbitrary, but rather opinions on beauty are largely shared across different sexes, cultures, sexual orientations, ethnic groups, and ages (Langlois & Roggman, 1990; Jones, 1996; Symons, 1979). Beauty is not in the eye of the beholder when judging facial appearance only.

Interestingly, physically attractive parents are 36% more likely to produce a girl as their first child compared to unattractive couples (Kanazawa et al., 2006). And males with feminine faces are more attractive than masculine faces to females; however, when the woman is most fertile, then she prefers masculine over feminine faces. This, of course, alters what secondary characteristics--and in what way--they are considered attractive.

Still, the most fundamental component of attractiveness is a configural one: irrespective of one's 'perspective', people tend to perceive those with low fluctuating asymmetry as most attractive. Belying this asymmetry is not genetic instruction per se, for the same genes code bilaterally symmetric features. Indeed, as someone noted, the cause of (FA) originates externally, in the womb, and then interacts with the gene's expression.

As for a quick comment on the evolution of attractiveness - in reality, beauty is not judged solely in the face, and nor is it wholly physical. If it was, we would see an evolutionary change. Instead, one's beauty extends to hairstyle, clothing style, body mass, and non-physical attributes...such as gait, attitude, dominance, loyalty etc. And, as it is, these assets of beauty are--in fact--in the eye of the beholder.

Originally Posted by Xaqaria

Although I do agree with your point about good genes, since there really is no such thing, there have been studies done showing that beauty is somewhat universal; I remember a particular one in which pictures were shown to infants and their reactions were gauged and judged to be more positive towards the same people. Things that are more symmetrical are generally more pleasing to the eye.

The good genes thing is a good point. The only "good genes" are the ones that persist.

That is extremely interesting Xaqaria. Do you think it's possible to find where you remember reading about that study? If it's been a while then, it's no big deal but I would really like to see that. That does add a different light to this for sure.

Originally Posted by Quark

To the other posters, facial attractiveness is not arbitrary, but rather opinions on beauty are largely shared across different sexes, cultures, sexual orientations, ethnic groups, and ages (Langlois & Roggman, 1990; Jones, 1996; Symons, 1979). Beauty is not in the eye of the beholder when judging facial appearance only.

Interestingly, physically attractive parents are 36% more likely to produce a girl as their first child compared to unattractive couples (Kanazawa et al., 2006). And males with feminine faces are more attractive than masculine faces to females; however, when the woman is most fertile, then she prefers masculine over feminine faces. This, of course, alters what secondary characteristics--and in what way--they are considered attractive.

Still, the most fundamental component of attractiveness is a configural one: irrespective of one's 'perspective', people tend to perceive those with low fluctuating asymmetry as most attractive. Belying this asymmetry is not genetic instruction per se, for the same genes code bilaterally symmetric features. Indeed, as someone noted, the cause of (FA) originates externally, in the womb, and then interacts with the gene's expression.

As for a quick comment on the evolution of attractiveness - in reality, beauty is not judged solely in the face, and nor is it wholly physical. If it was, we would see an evolutionary change. Instead, one's beauty extends to hairstyle, clothing style, body mass, and non-physical attributes...such as gait, attitude, dominance, loyalty etc. And, as it is, these assets of beauty are--in fact--in the eye of the beholder.

Damn good post I can attest to this, it makes perfect sense.

Originally Posted by ShadowNightWing

That is extremely interesting Xaqaria. Do you think it's possible to find where you remember reading about that study? If it's been a while then, it's no big deal but I would really like to see that. That does add a different light to this for sure.

I did a quick search and was able to find This Article, it seems like its talking about the same study.

Interesting you should bring this up:
http://news.bbc.co.uk/2/hi/uk_news/6057734.stm
http://www.dailymail.co.uk/sciencete...t-species.html
http://www.livescience.com/technolog...tic_class.html

And one article of particular interest:
http://www.scientificamerican.com/ar...uman-evolution

Comparing the amount of genetic differentiation between humans and our closest relatives, chimpanzees, suggests that the pace of change has accelerated to 10 to 100 times the average long-term rate, the researchers write in Proceedings of the National Academy of Sciences USA.

Humans are evolving at the fastest rate in history, and scientists do, in fact, predict a great split will occur, beginning as early as the year 3000. Why it has not happened yet? Take a glimpse through history. Many marriages were arranged, society got in the way, people didn't care, etc. etc. Plus, evolution is a long-term process. Humans have been here, what, under 70,000 years or so? As a species, we are still relatively young.

"The descendants of the genetic upper class would be tall, slim, healthy, attractive, intelligent, and creative and a far cry from the "underclass" humans who would have evolved into dim-witted, ugly, squat goblin-like creatures."

Has this not happened already? One foot into my local pub supports this divide.

The answer is: it's because beauty is relative. Just like characteristics are selected, taste is selected. What individuals of a population seek changes as the species undergoes natural selection. There's no sense in being satisfied with everyone - an individual must always go after the most beautiful (and by beautiful I mean adapted).

Originally Posted by Mario92

Interesting you should bring this up:
http://news.bbc.co.uk/2/hi/uk_news/6057734.stm
http://www.dailymail.co.uk/sciencete...t-species.html
http://www.livescience.com/technolog...tic_class.html

And one article of particular interest:
http://www.scientificamerican.com/ar...uman-evolution


Humans are evolving at the fastest rate in history, and scientists do, in fact, predict a great split will occur, beginning as early as the year 3000. Why it has not happened yet? Take a glimpse through history. Many marriages were arranged, society got in the way, people didn't care, etc. etc. Plus, evolution is a long-term process. Humans have been here, what, under 70,000 years or so? As a species, we are still relatively young.

Forgive my skepticism, but i see predicting the future in many regards as a fools errand. We can no more accurately predict the trends that will shape the next thousand years as the best alchemists and philosophers of the past thousand.

Originally Posted by Soros

Forgive my skepticism, but i see predicting the future in many regards as a fools errand. We can no more accurately predict the trends that will shape the next thousand years as the best alchemists and philosophers of the past thousand.

Granted, but we can also look at general trends in human history and genetic inheritance to form a general idea of what the future may have in store. Besides, this idea makes sense. Why shouldn't there be a split? People with traits GENERALLY considered as "beautiful" would be more likely to get together (staying within one's league, so to speak). The less attractive, being unlikely to marry a supermodel, would mate with other less attractive people. A schism would be logical.

Originally Posted by Mario92

Granted, but we can also look at general trends in human history and genetic inheritance to form a general idea of what the future may have in store. Besides, this idea makes sense. Why shouldn't there be a split? People with traits GENERALLY considered as "beautiful" would be more likely to get together (staying within one's league, so to speak). The less attractive, being unlikely to marry a supermodel, would mate with other less attractive people. A schism would be logical.

If such a thing would occur, this would me much greater than any class split found in the United Kingdom or the caste system of India. In this modern age, i find such a thing hard to fathom;especially considering that the chains of social class and caste have largely been disintegrating over the last 300 years.

If i am to take the theory seriously, then there will be a huge divide between the bourgeois so to speak and the proletarians that will stop the populations from mixing together even though the exact opposite has been happening.

I don't see this happening in the foreseeable future.