An investigative psychologist, Dr Evans, is studying the development of chronic aggressive behaviour in young adults. He notes that while individuals with a specific low-activity variant of the MAOA gene are more likely to exhibit aggression, this pattern is almost exclusively observed in those who also experienced severe childhood abuse or trauma.

With reference to Dr Evans' study, discuss the nature/nurture debate in psychology. Refer to the diathesis-stress model and/or interactionism in your answer.