 Our median life expectancy is 78.5 years, up from 38.3 150 years ago. The average income of the lowest-paid worker is seven times what it was in 1850. The average IQ has gone up by 35 points since 1916. In past plagues, people have died while trying to make it down the street, and the bodies have piled up on the sidewalks. That is not happening to us. We have one more reason to be thankful.