For over a hundred years, psychologists and human biologists have been engaged in an often heated debate as to whether 'heredity' or 'environment' should be viewed as the determining factor in the creation of the human personality. For teachers and educationists, the discussion has tended to focus on how the human mind functions and intellectual powers develop. The controversy is often simply expressed in terms of 'nature' versus 'nurture,' with some scientists declaring that human beings are a product of a transaction between the two. To many, such enquiry and speculation is little more than futile and depressing. Yet it can surely be argued that at least with regard to the development of abilities, the 'nature' versus 'nurture' debate has had dire consequences for the education of millions of young people. Furthermore, we need to question why this debate has been pursued with such vigour in both Britain and America.