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Why DO teens do THAT? Raging hormones? Prefrontal cortex fully developed? Thrill Seeking? New research from The Annenberg Public Policy Center of the University of Pennsylvania has released a report explaining Why Teens Take Risks: It's Not a Deficit in Brain Development:
The authors propose an alternative model that emphasizes the role that risk taking and the experience gained by it play in adolescent development. This model explains much of the apparent increase in risk taking by adolescents as "an adaptive need to gain the experience required to assume adult roles and behaviors." That experience eventually changes the way people think about risk, making it more "gist-like" or thematic and making them more risk averse.
"Recent meta-analyses suggest that the way individuals think about risks and rewards changes as they mature, and current accounts of brain development must take these newer ideas into account to explain adolescent risk taking," said co-author Valerie Reyna, Ph.D., director of the Human Neuroscience Institute at Cornell University.
Romer[1] added, "The reason teens are doing all of this exploring and novelty seeking is to build experience so that they can do a better job in making the difficult and risky decisions in later life – decisions like 'Should I take this job?' or 'Should I marry this person?' There's no doubt that this period of development is a challenge for parents, but that's doesn't mean that the adolescent brain is somehow deficient or lacking in control."
[1] Daniel Romer, Ph.D
Daniel Romer, Valerie F. Reyna, Theodore D. Satterthwaite. Beyond stereotypes of adolescent risk taking: Placing the adolescent brain in developmental context. Developmental Cognitive Neuroscience, 2017; 27: 19 DOI: 10.1016/j.dcn.2017.07.007 (Javascript required).
Alternate Link: Science.
(Score: 2) by Grishnakh on Monday August 28 2017, @04:33PM (6 children)
Humans don't on average have great eyesight.
Huh? This isn't true at all. Leaving aside people with actual visual problems (who wouldn't be alive in a pre-technological society, and wouldn't breed more people with visual impairments), humans actually have very good vision. Sure, other animals do have better vision by certain metrics, useful for particular tasks or environments, but overall humans do see very well. Cats can see better at night, but they're very near-sighted too. We can see quite well at a distance. Deep-sea creatures like octopi can see much better on the ocean floor because their receptors are pointed forwards instead of backwards, but those creatures can't handle seeing in the full sunlit-brightness of midday on land that we can. Lots of animals are color-blind to some extent; humans have a very full range of color perception.
Like so many things, our vision is a trade-off. Other animals get better night/low-light vision, or better far-sighted vision (like raptors that can spot mice while they're flying), but for the environment we live in, our vision is quite good and we have some advantages other animals don't because they made a different trade-off.
As for impairments, that's mainly a product of our current technological society, and also the way we grow up. There's evidence that kids growing up looking at close-up screens too much and not getting outside enough leaves them near-sighted.
Cataracts aren't unique to humans; lots of animals have similar vision problems as they age. We see it in pets all the time. You don't see it in the wild because wild animals don't live long enough for vision problems to be noticeable; if they do get that old, the vision problem contributes to their demise. Old animals that don't see too well end up being eaten. Lots of other diseases aren't unique to humans, such as cancer. Again, it's not seen much in the wild because those animals don't live long, and become some other animal's dinner.
(Score: 2) by Thexalon on Monday August 28 2017, @05:22PM (5 children)
Some of the known limitations of human vision:
- Humans, unlike some other animals, cannot see infrared or ultraviolet. The only reason we're not considered partially color-blind is that we're the ones deciding what constitutes a color we should be able to see.
- Humans have a relatively limited field of vision, unable to see things that are to the side of us or behind us. Other animals such as pigeons can and do notice things behind them.
- As you mention, we have neither the long-range precision of raptors nor the night-vision of cats.
- You also mentioned the people with actual visual problems, and promptly dismiss it as a non-issue. Except it isn't, because it turns out a majority of people in places with fairly easy access to glasses / contacts need them. That's a pretty strong indication that no, human vision is not 20-20 on average.
We're certainly not the worst off when it comes to our ability to perceive EM waves heading towards us, but to claim we're in great shape is also incorrect.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by Grishnakh on Monday August 28 2017, @05:46PM (4 children)
Yes, but for every example of an animal that has some super-human vision in some category, I'm sure I can point out how its vision is deficient in some other category.
Humans, unlike some other animals, cannot see infrared or ultraviolet.
Ok, but what animals can see well in those spectra? (I can only think of insects; their eyes have their own disadvantages.) I'm sure they have some deficiency too.
Humans have a relatively limited field of vision, unable to see things that are to the side of us or behind us. Other animals such as pigeons can and do notice things behind them.
Most prey animals have a wider field of view than we do. We're not prey animals, so we focus more on binocular vision. Animals with an extremely wide field of view generally have poor binocular vision, so they'd make terrible predators. Cats have a terrible field of view, probably worse than ours. But they're the pinnacle of land-based predators. There's a trade-off between field-of-view and binocular vision.
As you mention, we have neither the long-range precision of raptors
I'm not an ornithologist, but I imagine raptors would not do very well with looking at stuff close-up. They might not have our color vision abilities either. I'm sure there's some deficiency there.
nor the night-vision of cats.
Cats have terrible long-distance vision: they're myopic. I think they're partly color-blind too. They probably can't handle brightness as well as we can either. But they're great at hunting small animals at relatively near distances at twilight or at night.
but to claim we're in great shape is also incorrect.
I don't think it is. It depends on your metric. For the lives we lead, our vision suits us well, and that's no coincidence. For the lives octopi lead, their vision suits them well too, but their vision would not suit us well at all. I'd rather have stronger binocular vision than a near-360-degree field of view, and I'd rather have the color vision I enjoy now than crappy color vision but with UV ability.
Except it isn't, because it turns out a majority of people in places with fairly easy access to glasses / contacts need them.
Has anyone ever done a study to see if people in primitive pre-contact hunter-gatherer tribes need them? Modern life simply isn't like the lives we led during the vast majority of our evolution, so it's no surprise we're running into issues with our physical bodies. And there really aren't very many people left not living a modern life (and those tiny few that are in the Amazon, we don't talk to them and certainly don't do experiments on them to see if they need glasses).
(Score: 3, Informative) by Immerman on Monday August 28 2017, @06:42PM (3 children)
I believe most birds have at least a fourth set of cone pigments allowing them to see well into the ultraviolet -I've heard pigeons are actually brilliantly colored to other pigeons. Octopi have only one set of broad-spectrum receptors, but appear to use chromatic aberration to achieve color vision by another method (though I'm unclear as to how their total spectral range compares), plus they can see polarization, and their eyes are mobile enough to allow either near-360 or binocular vision. Mantis shrimp have 16 different color receptors, and can actually tune the frequency sensitivity of their long-wavelength vision to better suit the environment.
Cuttlefish have the same basic poorly-understood visual system of octopi, but actually have two fovea, so that they can simultaneously focus behind and in front of themselves (and have binocular vision).
Lots of species can see polarization - a visual ability which we completely lack.
Raptors eyes pretty much blow ours away in both color range and acuity - their only weakness seems to be terrible night vision.
Basically - yes, our eyes are pretty good for what we need them for, but they are far from the best. Not in any specific application, or even in general capacity. They're just what we're accustomed to, and so become the baseline against which we measure others. Basically, our vision hasn't been our species big advantage since long before we became human, and so evolution hasn't really done much to it except keep it from degrading too badly.
(Score: 2) by Grishnakh on Monday August 28 2017, @07:05PM (2 children)
Basically - yes, our eyes are pretty good for what we need them for, but they are far from the best. Not in any specific application, or even in general capacity.
Again, I completely disagree. You need to point out some animals which have significantly better vision in all ways than ours, and which have *zero* disadvantages. I don't think you'll find a single one.
Raptors eyes pretty much blow ours away in both color range and acuity - their only weakness seems to be terrible night vision.
And here's a good example here. Night vision is pretty important: we're awake for at least 16 hours a day, so we do need at least somewhat-decent night vision. Maybe not as good as cats', but certainly not "terrible".
Every species is the same way: its vision is tuned for the environment it lives in, and the way it lives, and on top of that it has to fit in with the rest of their bodies and work with their brains.
and their eyes are mobile enough to allow either near-360 or binocular vision.
Yeah, and octopi don't have any bones either which makes that possible. How well would we survive without any skull bones? Not very well. And I'd like to see how well octopi can see outside, on land, in the middle of the summer at the brightest point of the daytime. We can handle that just fine, perhaps with a bit of squinting. Sea creatures are not going to have eyes evolved for extreme brightness as found on land.
Basically, our vision hasn't been our species big advantage since long before we became human
I challenge you to find any animals with vision that's better in every single metric.
To use a car analogy, this is like arguing whether sports cars, pickup trucks, or Priuses are better. I'd like to see a Prius or sports car that can pull a boat, and I'd like to see a pickup truck that gets 50mpg or can handle the way a sports car does. There's never any one thing that's clearly better in every single metric.
(Score: 2) by Immerman on Monday August 28 2017, @07:36PM (1 child)
Better in every single metric is ridiculous. I challenge you to find any vision-heavy species whose vision is *worse* than ours in every single metric. That should be easy if ours is truly "the best" in any meaningful form, right?
Better overall/on average is pretty much the only metric that makes any sense when comparing between very different systems. And by that standard ours vision is... okay. Maybe even pretty good.
(Score: 2) by Grishnakh on Monday August 28 2017, @08:03PM
I challenge you to find any vision-heavy species whose vision is *worse* than ours in every single metric.
I never made any such claim. Lots of species have vision that's better in some metric than ours. I don't think any has vision better in *every* metric. That's the whole nature of a trade-off.
Are you not an engineer?
That should be easy if ours is truly "the best" in any meaningful form, right?
I never said humans have "the best" vision, only that it's the best for our particular niche. Many other animals have "the best" vision for their own niche. Octopi have great vision in many ways. But they don't live on land, and we don't live on the ocean floor, (and we don't have boneless bodies either) so their vision isn't suitable for us, nor vice-versa.
And by that standard ours vision is... okay. Maybe even pretty good.
And which species exactly has superior vision?