Click on any phrase to play the video at that point.Close When
you have 21 minutes to speak, two million years seems like a
really long time. But evolutionarily, two million years is
nothing. And yet in two million years the human brain has nearly
tripled in mass, going from the one-and-a-quarter pound brain of
our ancestor here, Habilis, to the almost three-pound meatloaf
that everybody here has between their ears. What is it about a
big brain that nature was so eager for every one of us to have
one? Well, it turns out when brains triple in size, they don't
just get three times bigger; they gain new structures. And one
of the main reasons our brain got so big is because it got a new
part, called the "frontal lobe." And particularly, a part called
the "pre-frontal cortex." Now what does a pre-frontal cortex do
for you that should justify the entire architectural overhaul of
the human skull in the blink of evolutionary time? Well, it
turns out the pre-frontal cortex does lots of things, but one of
the most imp