Transcript

When you have 21 minutes to speak 2 million years seems like a really long time. But evolutionarily 2 million years is nothing. And yet in 2 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 than gain new structures. And one of the main reasons that our brain got so big is because it got a new part called the frontal lobe and particularly a part called the prefrontal cortex. And what does the prefrontal cortex do for you, that should justify the entire architectural overhaul of the human skull in the blink of evolutionary time? Well, turns out the prefrontal cortex does lots of things. But one of the most important things it does is it isn't experience simulator.