The psychological study of intelligence has a long and controversial history. There is general agreement that it is possible to measure cognitive abilities and to put people in a rough rank order. There is also general agreement that we can use these scores to predict success at work and in education. Where the disagreements come is in the causes of these differences and what interventions we should make to respond to them. The answer you come to will depend less on your reading of the scientific evidence and more on your view of what it means to be a human being.