Oh Sweet, Sweet Science. I Love When You Vindicate Me.

I've been saying that short people have it better for years, especially when it comes to the *ahem* lower extremities. Now neuroscientist David Eagleman proves me right.

From NPR's: All Things Considered, May 18, 2009 · (The link will take you to the audio story as well.)

The Secret Advantage Of Being Short

In which it is explained why short people have it better.

From the story:
"If I were to stand on your left side and snap my fingers next to your left ear, you would hear one snap. It would be a little louder on your left side, but still it would register as one snap.

If you think about that, you might wonder: How come I didn't hear two snaps? After all, the sound entered your left ear right away and had to travel around your head into the right ear (which must have taken a little time). So your right ear heard it a little later, and yet it registered as one simultaneous event."

This is apparently called "temporal binding": The brain synchronizes events, despite differences in the timing of incoming sensory data, which gives us the feeling of simultaneity.

Eagleman proposes that "if the brain wants to get events correct timewise, it may have only one choice: wait for the slowest information to arrive.

To accomplish this, [the brain] must wait about a tenth of a second. In the early days of television broadcasting, engineers worried about the problem of keeping audio and video signals synchronized. Then they accidentally discovered that they had around a hundred milliseconds of slop, and as long as the signals arrived within this window, viewers' brains would automatically resynchronize the signals.

This brief waiting period allows the visual system to discount the various delays imposed by the early stages; however, it has the disadvantage of pushing perception into the past. There is a distinct survival advantage to operating as close to the present as possible; an animal does not want to live too far in the past. Therefore, the tenth of a second window may be the smallest delay that allows higher areas of the brain to account for the delays created in the first stages of the system while still operating near the borders of the present.

There's another way to think about this, Eagleman says. If a person touches your toe and your nose at the same time, he says, "you will feel those touches as simultaneous. This is surprising because the signal from your nose reaches your brain before the signal from your toe. Why didn't you feel the nose touch when it first arrived?

It may be that our sensory perception of the world has to wait for the slowest piece of information to arrive, Eagleman says.

Given conduction times along limbs, this leads to the bizarre but testable suggestion that tall people may live further in the past than short people.

"Because for the taller person it takes a tenth of a second longer for the toe-touch to travel up the foot, the ankle, the calf, the thigh, the backbone to the brain, the brain waits that extra beat to announce a "NOW!" That tall person will live his sensory life on a teeny delay (at least as regards toe-touching). This, of course, could apply to all kinds of lower-extremity experiences — cold or heat against the skin, tickles, rubs, hitting a soccer ball — the list goes on and on."