I THINK it's because... (this is by a 13 year old so if I make any mistakes I'm sorry.) In the animal kingdom the males are the ones who are more phsyicaly attractive because they're the ones who attract their mate. Since they are the ones particularly interested in mating, not usually the female, they are the ones who seek out a partner during mating season/when female is in heat/when they want to, therefore they are equiped with such features to attract females, either colorful feathers, bug tusks, plenty of times the size and strength. They also use this to compete with other males for the female. In the case of humans though, we have a more complex way of looking at mating. Our minds are more developed than animals and we may very well say that both sexes want to attract each other. Women make themselves prettier, men try to look more handsome and muscular. But we think way beyond that concept. We see our physicial appearance not only for seeking out partners but also for many reasons, ei self-satisfaction, blah blah blah. So for short, animals have such a straight-forward way of looking at physical appearances and other sexes that they have simple reasons for their own appearance and behavior towards their own and to other sexes. While in the case of human beings, it's a lot more complicated and our appearances have a much more vast meaning to us.

Hi there, I’ll make a try too, although I’m not an expert in this. In many animal species the male is the more colorful and ornamented because he does not have to carry and nest with the young (well, more often), and so he can be extravagant in attracting mates. The female needs to be camouflaged and inconspicuous to avoid attracting predators while encumbered by pregnancy or when hiding in a nest (den, etc.) with the newborns. In many species the male has no part in this childcare, so has less selective pressure against ostentatious display. Also, the male can attempt to mate many times with multiple females with little biological expense, so he has even more advantage in an effective display to attract many mates. The female needs to expend a tremendous amount of biological energy and risk, in many species, in producing, protecting, and caring for her babies. She is the one who needs to be the picky mate-shopper to choose a mate whose genes are worth all this investment in energy and danger. This said, there are many species in which the male is not more colorful or overtly attractive. This could be either be because 1) he has the same motives as the female, in some species in protecting and caring for the young, or 2) because of other selective pressures on his appearance. In the first case, there are species in which the male takes as active a role in caring for vulnerable youngsters as the female. All that comes to my (little) mind now are sea horses, penguins, and a fish (where the eggs are taken in the male’s mouth). I believe all these species do not have extravagant males. (Some seahorses are a bit showy, but that’s camouflage, and the females should have it too, if I’m right). In the second case, there are many fish where the male and female are virtually indistinguishable. Fish have a tremendous selective evolutionary pressure on their shape to be stream lined to be hydrodynamically streamlined and swift so as to avoid predators and catch prey. A fish with a rooster’s comb could not swim as fast! (Also, in some cases the young male grows and changes into the larger female.) Where do humans fit into this? In humans, the females are the ones who have the most need to be physically fit and young to successfully carry to term and raise for many years the human young (shall we term them, “children”?). A (reproductively) successful male would have evolutionary pressure to choose females who are physically fit and “pretty”, Women do in fact display larger breasts and hips than the males to advertise these features useful in reproduction and child rearing. However, males have both these features too, although not as pronounced. Also, in humans, unlike many species, it is common for the males to bond long term to the females, and share in caring for the young. So, he has some evolutionary pressure to not be too showy and physically extravagant (think peacock feathers) or he could not hide with the young family and be fit enough to defend and feed them. On the other hand, the female does have a biological interest, as in many species, in being picky and choosing the best mate to provide good genes for the small number of offspring she will have in her life (compared to hundreds of baby spiders) and to help her raise the children. Because the male has the reasons mentioned not to be physically showy, instead he can be socially showy and get a prestigious job, drive a nice car, be intellectually interesting or cool, and know detailed sports statistics (well, 3 out of 4 ain’t bad). Thus, I’m suggesting that in humans we think of the female as prettier because there are reasons for the male to seek a mate who is young and physically fit for child rearing, but in fact neither sex is physically very showy, because both hide in the cave, or wherever, protecting the children when they are young and helpless, and both are rather slow compared to big predators (lions and tigers and bears, oh my!). Human males do not have colorful combs, or inflate brilliant neck pouches, but neither do females. Males have no large extremity that the female doesn’t, except one organ that is strictly practical for reproduction (no, not the adam’s apple). Beauty is in the eye of the beholder, but objectively neither human sex is very showy. So, the shorter answer is 1) human females need to display “prettiness” to show they are healthy enough to produce and raise healthy babies. 2) Males cannot be too showy or colorful or they would be less effective hiding in the “den” with the slow helpless children, they might attract predators, be less effective finding food, and their social status may be as important in making them fit parents. 3) We think of females as prettier because males seek healthy mothers, but neither sex actually has conspicuous physical display compared to the really showy species. Sorry if that was awfully long winded and disorganized, but maybe there are some possible ideas in there.

With humans girls (I know this 'cause I am one) have more choice in what to wear like pants, shorts, skirts, and dresses.But with guys they'd rather look tough than handsom.Besides girls shop for clothes as a hobbie as something to do, when boys mostly shop for skate boards and motorcycles.Basicly girls can do more with their look than guys can.