Eugenics, or the science of human breeding, has been used to justify some of the worst atrocities of the 20th Century, but it has been with us since the beginning of time. Whenever a couple has a baby, that are engaged in a eugenics experiment. Demographic philosopher Glenn Campbell reviews what eugenics can and cannot do and what the earliest proponents got wrong. The best aim of eugenics is not to create a master race but to assure diversity.