Since my most popular post to date has been a review of Mean Girls, and since I've been meaning to partially review some of the movies in my Netflix queue, why not kill two birds with one stone and write a follow-up? I've been watching more teen movies than I should, but I was pretty clueless about adolescent girl life when I was a teenager myself, and given how important this time of your life is -- the tumultuous, transient state before you reach equilibrium -- the anthropologist in me wants to figure it all out and try to account for it. The guy part I pretty well understand from personal or one-degree-removed experience, though I note below some things that I was oblivious to at the time as well.
1) To get the superficial out of the way first, I've learned that of all the aspects of a female's physical appearance, the one that most honestly signals youthful fertility is tight skin, not just in the face but in general. For those who don't work with teenagers or college students, just remember: what items of clothing does almost every 18-ish girl wear, which disappear by just age 25? Hot pants and mini-skirts, which show off the legs -- not their length (females obsess over being tall later), but rather the tautness of the skin. This is true even if the girl isn't very athletic and so lacks muscular legs; it's mostly a bunch of fat that's nevertheless held tightly together. It looks like an inflated balloon stuffed with Jell-o, which as she ages resembles Saran wrap struggling to conceal porridge. The fatty deposits and lack of large muscles signal femininity, while the tight skin signals youth. After, I'd say, a girl's mid-20s (on average), only one of these becomes possible to maintain -- either a doughier appearance as the skin slackens around the fat, or a tightness achieved by vigorous exercise to burn off the fat and expand the muscle.
As a few examples, consider that three of the four main characters in Mean Girls are 18-22, and the exception (a 26 y.o. Rachel McAdams) opts for the treadmill junkie look to pass as younger. Also, in Never Been Kissed, only one of the main female characters (played by an 18 y.o. Jessica Alba) is of high school age, and she is the only one who wears hot pants consistently throughout the movie. The other three are 24-25 -- decades away from being old hags, but apparently past the point of being able to rock the hot pants. (Comparison here, and two more of Alba here and here.)
To prove that Alba's co-stars weren't always incapable of baring their legs, consider actress Marley Shelton: in the course of digging around for this post, I discovered that she played the red-hot lifeguard in The Sandlot. In case you haven't seen it, watch the famous pool scene here. It's clear that she too once had legs like Alba does in Never Been Kissed, but The Sandlot was made six years earlier, when Shelton was 19. Note that average human generation time is 20-25 years, so 25 does seem a natural point for the female body to begin its descent from maximum hotness, as it expects itself to have snagged a mate and born a child by then.
2) Related to a female's hotness during adolescence is her ability to enter a higher social stratum than that into which she was born. This is a pretty general pattern: guys are more locked into place since if they aren't already smart and/or wealthy, they won't be able to use their looks or charm to marry a smart / wealthy girl, whereas smart / wealthy guys are happy to take a trophy wife who may not be incredibly sharp or rich. Also, when more powerful groups invade and conquer another group, it's typically the native women (the best-looking among them, one assumes) who are absorbed into the conquering group, while native men are hung out to dry. For example, in Brazil about 97% of the male lineages are European (and 3% African), while those of females are fairly evenly split among European, Native, and African (39%, 33%, and 28%, respectively; the studies are listed at the end of Ch. 12 of Human Evolutionary Genetics).
Now, social strata in adolescence aren't distinguished so much by wealth as by popularity. There's a pretty easy way for a currently unpopular, newly arrived high school freshman to catapult herself into the popular peer group of senior jocks and other alpha males: assuming she's pretty, she can just put out. In contrast, it would be impossible for an unpopular freshman guy -- no matter how tall, hunky, and athletic -- to break into the ranks of hot senior cheerleaders.
3) As a result, adolescent females are locked in a much more bitter struggle with each other compared to male-male struggle. A senior cheerleader who's landed a hot popular boyfriend has to constantly chase away would-be trespassers in the three grade levels below her, many of whom would easily put out just to steal her glamorous boyfriend. This puts more pressure on the junior and senior girls to put out, lest their boyfriends leave them for more easily conquered freshman girls. A prediction is that Neuroticism in females will increase, or at least reach its peak, during adolescence, which recent personality trait studies have borne out (see here and here).
Adolescent males don't have to worry about this so much, as they don't really become desirable until they're juniors or seniors anyway. Thus, their would-be competitors -- guys who are 19-20 -- are nowhere to be seen. It's very rare for a high school girl to date a college guy, just because their social circles and daily routines don't overlap, so high school guys with girlfriends are well insulated from competition. Evolutionary psychologist Geoffrey Miller has made a similar point, although he went too far in suggesting that 18-23 y.o. girls would date guys in their late 20s or 30s if only there weren't artificial social barriers like socializing adolescents in a bubble (high school). Still, a watered-down version is tenable: if high school and college-aged people were socialized together, high school guys would suffer massively from college guy competition. This doesn't continue infinitely since, again, by about 25 you're clearly past the adolescent-adult threshold (excepting rareties like Jessica Alba or a younger Johnny Depp). And for those who think that being 25 doesn't make you a geezer, read this post to confirm that you are in fact an old fogey.
4) On a related note, though, an even greater effect of increased inter-generational mixing would, I think, be a decrease in caddish behavior among adolescent males. One of the girls I tutor (who just finished 11th grade) is the pretty, popular, cheerleader / athlete type. She's on the touchy side but is really a nice girl. One day before our session began, she had to get something off her chest, to warn me in case she wasn't able to focus very well: her boyfriend (the popular jock type) had been pressuring her to have sex, but she wouldn't budge. So, just one week before her birthday (!), her boyfriend dumps her, explaining that "I'm gonna see what I can get with someone else." I was praying that she wouldn't mention his name, because I would have hunted him down like the dog that he is (fortunately for him, she did not).
Even in a hunter-gatherer society, it doesn't require any brawn to kill someone -- just ballsiness and the element of surprise, such as a pre-dawn raid. And in a culture more advanced than an H-G one, populations are large enough for anonymity to protect an attacker from being found out. In our radical feminist society, though, guys aren't supposed to care about defending girls, since they supposedly can take care of themselves -- yeah right. In any civilized society, a girl's older brothers, cousins, and close male friends would give her cur of a boyfriend an intimidating warning, and failing any change on his part, beat him to within an inch of his life. But add to radical feminism the vast social chasm between adolescents and 25+ adults, and it becomes very difficult for would-be male protectors to stay in touch with who is dishonoring whom, and hence tough to keep the scoundrels in line.
When I casually mentioned around some 14-15 y.o. tutorees that if I ever have daughters, I'll punish their boyfriends should they misbehave, they responded like, "Oh my god, you're so clueless -- a girl would never tell her dad if something was going wrong with her boyfriend." It would seem to follow that any male of her dad's age wouldn't know either. So, it's crucial for brothers, cousins, and male acquaintances in their 20's and 30's to be part of an adolescent girl's social circle, so they can hear the bad news and straighten the offender out. In the present case, though, this responsibility falls on the shoulders of her adolescent male peers, who are too interested in her sexually to play the role of protector. And for the same reason, only the tiny minority of super-hot girls would receive protection (contra the definition of "White Knight Syndrome" above, which falsely states that White Knights try to help "any" girl in trouble, out of chivalry).
Ideally, older brothers and cousins would perform this role, since they are not interested in her sexually due to the incest taboo, as well as having a stronger protective instinct due to kin selection. If they aren't around, then males on the other side of the 25 y.o. age divide could step in, as the potential for mutual sexual attraction is minimal (unless he's Justin Timberlake), and assuming they are close acquaintances, they'll have a strong protective sense due to selection for reciprocal altruism. This is one case where neutral third parties, such as the police, could not be relied upon: cruelly mistreating a girl is not against the law. And that does make this case pretty dangerous, as it's easy to imagine feuds beginning with the male relatives of a girl ganging up on her degenerate boyfriend, whose relatives then retaliate. Still, I think if families were more in touch with what was going on in the community, the cad's family would be far outnumbered and would not be able to strike back, even if they wanted to.
5) Why are guys of any age far more likely to feel hyper-protective about the physical appearance of adolescent girls rather than older females (say, 30+), even if the older females are closely related (blood relative, wife, etc.)? In Mean Girls there is a hilarious scene in which Lindsay Lohan describes what Halloween parties are like for present-day American teenagers. Watch a 20-second clip that sums it up here. (Steve Sailer mooted this topic here, presumably without having seen the movie.) Note the expression of anxiety and helplessness on the father's face; obviously, any father would feel this way if his teenage daughter were going to a party in just lingerie, knee-high boots, and animal ears. (Also note how wimpy the modern American dad has become: if I were him, after I'd recovered from the nine heart attacks I'd had before I hit the floor, I'd lock her in her room until she dressed more tastefully.)
But throughout the movie, the script emphasizes his wife's desperate labors to act young and slutty. For example, she gets gigantic breast implants, wears a form-fitting pink tracksuit, offers her daughter a condom when she walks in on her making out with her boyfriend, and so on. Why doesn't the father weep in disgust at his wife's vulgar behavior? Well, her ship has already started to sink anyway, so why bother salvaging it if there is another intact ship that you see heading toward an iceberg? More to the point, though perhaps less tactfully, it's the same reason that we lock up our precious jewels in an airtight vault, while we leave our spare pennies just lying around in the open -- which ones are potential thieves interested in?
Take the example to the extreme: imagine your daughter was wearing a PVC bondage outfit a la Trinity from The Matrix. Your heart would race with anxiety about how she'd attract the filthy leers of every male in sight, and you'd send her off to boarding school. On the other hand, if your 35-40 y.o. sister were so dressed, you'd give her a calm but incredulous look like, "Who are you kidding, do you really think you can pull that off?" Or, "I just want to keep you from publicly embarrassing yourself." That is, unless she were a rare exception like 30-something Carrie-Anne Moss who played Trinity.
There are surely more lessons, but I've gone on long enough already. I'd just like to conclude this follow-up to the Mean Girls post, in which I griped about how I preferred Heathers, by noting that I've successfully managed to introduce the latter cult classic to some of my tutorees. Over the past several months, I've been tutoring kids for the SAT II Math 2C test, and in reviewing limits, I mentioned one of the final scenes of Mean Girls where Lindsay Lohan answers a limit question in a mathlete competition. The female students always react in a way indicating that this is one of their favorite movies, so I suggested that they watch the earlier Winona Ryder incarnation for comparison. One of my tutorees watched most of it on cable and said she liked it, even if dark humor wasn't her preference. On the last day I tutored her, she brought me a gift: a DVD of Heathers! I'd never received a gift from any student before, let alone one so awesome, so she is now officially the coolest student I've ever had. Now, if only I could get my male students to appreciate Nintendo and Super Nintendo video games, I'll have successfully passed on my generation's greatest cultural contributions.