the ground, oil, coal, if we keep using them, we would run out. maybe 500 years down the road, we would run out? >> if we keep using anything, essentially we're going to run out unless it regenerates, but we know that a couple hundred years from now we are going to discover all new ways to power our economy. if we decide we're going to leave the resources in the ground for conservation, what good is it doing us? we're using it because of enhanced health and human welfare. >> researching human fear, what differences have you found between what men fear and women fear? >> i haven't looked at a lot of gender differences in fear. startle response is universal. so humans are going to jump when startled by something, and then beyond that, it's going to depend on where a person is where, they grew up. their developmental history. john: i think women fear more stuff.