The Nativists argue that nature (the genetic coding) is responsible for a persons behaviour and overall performance in life. The Empiricists (not to be confused with the scientific methodologists) argue that the external environment is responsible for the individuals personality or behaviour through a process called conditioning. A third cohort also proposes that it is a combination of both forces but the precise degree of interaction on each side is still in dispute.
I have a case against each proponent. Concerning the Nativists: If nature is responsible for human behaviour then it implies that there is no freewill since a thief is genetically designed to be a thief. It also implies that without external stimuli, a child who inherited genes for intelligence should necessarily be successful and happy in life since nature has dictated that. But we all know this to be untrue.
My second case is against the Empiricists: If the external environment is responsible for human behaviour then how come two children from the same family, living under the same physical, economic, social and cultural conditions develop contrasting personalities sometimes to the extremities of good and evil. There are those who even say that humans have no fixed nature.
Concerning the third cohort, I think the degree to which nature and nurture influence the individual is not as important as the specific genetic information and how it is designed to react to various external stimuli – whether analogous or inverse. A typical example is how different people react to criticisms. Some react without processing, others process and then react, still others don’t process and don’t react. For those interested in further reading, there is an interesting article on the subject here. Happy weekend!