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 quotient” which 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 they’re 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.