19 Comments

Perhaps this is linked to the major pruning of synapses which takes place in the brain during adolescence.

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I've always thought that teens' propensity to stay up all night has an evolutionary reason. Similarly, re the propensity of the elderly to sleep lightly and restlessly at night. These habits make it more likely that, at night, there is someone vigilantly guarding the campsite or village. They also enable the most productive adults to rest as much as possible to work the next day, so a division of labor as well.

Somewhere on the savannah lie the bones of a family whose teenagers went to sleep "at a reaonable hour".

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There has never been a widespread, prolonged adolescent phase as we have now.

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Mark Kleiman has made the same point about the hour when school starts (though in the context of crime reduction). His view is that teachers and parents dropping off kids like the time to commute.

I was similar to Evan, but with a less diminished sense of smugness. I also oppose drug laws but look down on drug cartels, in the imperfect status quo they are engaging in unsurprising but destructive behavior. Three cheers for abject surrender.

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There has always been an evolutionarily important "young adult" period, no matter what it was called. Yes the environment has changed, but that applies to all ages; it doesn't mean teen behavior is less well adapted than other age behavior.

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What Evan said.

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Yes, it's been tested. It's fairly well established. And school officials ignore the findings.

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Nikki, remember Hanson's http://www.overcomingbias.c... ? Also the student comments at http://www.overcomingbias.c...

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‘Teenager’ is way too new a concept and life stage for there to be almost any evolutionary history associated with it. Whatever evolutionary pressures shaped personality development in the past are likely to now be absent or so different as to be unrecognizable. This is actually the key. "Teenager" did not exist as a concept in the past, instead people of that age were generally treated as adults. So their minds have evolved to expect to be treated as adults. When they are treated as children instead they get understandably upset. It has nothing to do with powerful hormones and everyone to do with being treated badly by adults.

If the government monitored your behavior constantly, controlled what time you could leave your house, controlled what media you were allowed to read and watch, wouldn't let you have sex, and forced you to work at a boring job eight hours a day for free, you'd get pretty mad too. Parents who complain that their teenagers are ungrateful because they've given them a lot of time and effort are completely missing the point. That's like a totalitarian government complaining that their citizens are ungrateful for wanting freedom of speech when they've given them free food and health care.

So why do teenagers actively resist maturity? Because in the ancestral environment, one response to persecution was to band together with other persecuted people and form your own distinct counter-faction or tribe. The instinct to do that still exists, even though it doesn't make much sense in this context. So teenagers band together and form their own subculture that is distinct from the adults. This subculture develops its own values that actively reject the values of the culture they oppose. This includes the value of maturity.

So why do teenagers decline in maturity? Short answer, because they live in a totalitarian society.

***Note that I am not a teenager, and that when I was I an extremely well-behaved homebody who didn't understand why the other teenagers were being rebellious. It wasn't until much later that I realized the reason I was so mellow was because I didn't want to do any of the things most teenagers are upset that they aren't allowed to do. In other words, like a lot of people, I was only defending the freedoms that I was using, and ignoring the abridgement of freedoms that I had no use for. It's a mistake that I'm ashamed of, and that I'm trying to correct for.

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Yes, there definitely has been research.

I think one of the reasons for ignoring the findings has to do with how life in some ways has been getting easier and easier in the West so that each generation ends up thinking the one after them is in some way behaving in a lazy manner--creating a bias in our interpretation of adolescent behavior.

Adolescents reporting wanting more sleep translates as laziness in the minds of many adults, laziness that needs to be disciplined. Indeed discipline is in order, but wrongly placed discipline may actually be wasting money put into education.

Traffic is a relavant matter. I wonder how much it factors into policy decisions regarding education.

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This looks like an example of counter-signaling. Assume teens and adults are capable of sending a "maturity" signal, though kids are not. Most adults send the maturity signal so at first glance we have a separating equilibrium. Teens counter-signal by sending an "immaturity" signal to distinguish their type from adults. This assumes that "teens" and "adults" are not entirely determined by age or there would be no need for signaling and counter-signaling.

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Personally, I would love to see how maturity changes over a human 1000-year life span. Get enough people to live for a very long time, and that would be one hell of an interesting experiment.

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"Most likely the education they get while in the High School years would be more effective if school started later."

This hasn't been tested yet? It seems so easy to do, low hanging fruit.I understand school bus systems and maybe rush hour traffics are the primary reasons for early school starts, but if one could demonstrate huge achievement benefits for specific age groups from different study/sleep cycles it would at the least result in a payoff of academic celebrity.

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'Teenager' is way too new a concept and life stage for there to be almost any evolutionary history associated with it. Whatever evolutionary pressures shaped personality development in the past are likely to now be absent or so different as to be unrecognizable.

If these patterns persist, that is not a validation of their usefulness in the modern world. It only means that they are not so destructive as to decrease reproductive fitness. Evolution isn't careful optimization, it is the elimination of the totally unworkable.

--Leah @ Unequally Yoked

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My own thought exactly. We're going to use one famous decline in maturity for 10 years or so, with an obvious cause (puberty), to argue against any overall increasing trend over the human 120-year lifespan?

That's a serious stretch. It'd be like saying, the folk theory that we mature as we age is clearly incorrect because, as measured by the latest psychological tests, babies become less mature and more unpleasant to others when they reach the Terrible Twos.

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My interpretation would be that (i) our behavior is almost entirely determined by the levels of various hormones, (ii) what we consider "mature" behavior is simply the behavior produced by hormonal levels that characterize adults and (iii) there is no particular reason to assume that the behaviors characteristic of each age are adaptive, it might be that there are other reasons for the hormonal levels in question, and the resulting behaviors are pure artificacts.

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