Placeholder Image

字幕表 動画を再生する

  • I like big brains and I cannot lie, those other guys can’t deny when a girl walks

  • in with a….

  • wait hold on, does a big brain actually mean more intelligence? or does it just mean a

  • big head?

  • Hey guys

  • You know what they say, the bigger the better, right?

  • So does that hold up for noggin size too?

  • Well in a way.

  • We like to think big brains mean more smarts.

  • Bigger is better right?

  • Not really.

  • Big brains aren’t unique to humans, whales and elephants also have large noggins.

  • Compare an average blue whale brain to an average human brain: blue whales, 15 pounds,

  • average human brain, 3 pounds.

  • But even though their brain is five times heavier, humans come out on top.

  • So what’s going on?

  • So maybe the weight of our brain isn’t the right way to look at it, maybe it’s a comparison

  • to body weight.

  • In that case, blue whales have a relatively small brain; it’s only 0.007% of its body

  • weight.

  • While human brains are about 2% of body weight.

  • and comparing ratios.. well that still doesn’t tell the whole story either.

  • Humans have a 1:40 ratio, but that’s about the same as a mouse.

  • And elephants which many consider to be pretty smart cookies have small, 1:560 brain to body

  • ratio.

  • So a really smart animal might have a large ratio and on the other a not so bright critter

  • like the tree shrew has a relatively large head compared to it’s body size, 1:10.

  • So not an ideal measurement either.

  • So researchers found a way to put humans in their rightful place

  • well, not really.

  • They created the "encephalization quotientwhich is similar brain to body ratio, but

  • it takes into account the fact that some parts of the brain like the part that controls breathing,

  • is the same size across species.

  • So the EQ also includes a comparison of similarly sized animals.

  • The formula looks like this ___

  • And according to this measurement, humans dominate.

  • On the higher end, humans have an EQ of 7.8, elephants- only 2.36, which is similar to

  • chimps, who rate at 2.5.

  • Which sort of seems right when it comes to ranking intelligence.

  • But maybe size has less to do with intelligence than we thought.

  • Some scientists say the EQ it’s not an accurate way to judge intelligence and that other features

  • of the brain matter more.

  • Like the development of certain parts of the brain like the cerebral cortex or the number

  • of folds in the brain which increase surface area.

  • Maybe it’s the way the brain signals.

  • One study published in the journal Nature Neuroscience found that maybe it’s not the

  • size, but the underlying structure and molecular signalling at the synapses.

  • Synapses are those points between neurons which exchange information.

  • The researchers examined molecular signaling across various species like yeast, fruit flies,

  • and mice.

  • They found that most species have the same proteins in the synapses.

  • But it’s the number interactions and gene duplications of these proteins that begin

  • to show differences in intelligence.

  • The basic proteins found in yeast can also be found throughout the brain in regular amounts

  • kind of like a foundation made out of bricks.

  • But the researchers say that it’s the way these proteins interact and the number of

  • duplications that evolved into regions of higher thinking.

  • So like bricks in a house, it’s how many and how theyre put together that make a

  • strong building.

  • And maybe it’s the size of different regions of the brain that matter.

  • Take a look at Einstein, widely considered to be one of the smartest people to ever grace

  • this planet.

  • His brain?

  • Not so big.

  • Kind of average actually.

  • Though there might be some evidence that his inferior parietal lobe was 15 percent wider

  • than normal, and that part of the brain has been linked with mathematics and spatial processing.

  • So what’s the verdict?

  • Size doesn’t always matter, but maybe connections do.

  • Curious about how we judge the intelligence of other animals?

  • Check out this video from Trace on animal self awareness.

I like big brains and I cannot lie, those other guys can’t deny when a girl walks

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B1 中級

脳の大きさが問題なのか? (Does The Size Of Your Brain Matter?)

  • 45 5
    chung に公開 2021 年 01 月 14 日
動画の中の単語