The question of "Nurture vs Nature" to explain human behaviour has long interested psychologists and philosophers. Behaviourists believed the answer was definitely "Nurture"- everything about our behaviour can explained in terms of our environment. The most radical behaviourists believed that everything about human behaviour could be explained by studying rats in mazes. Today, however, behaviourism is a defunct research project. We discuss why behaviourism rose to dominate the field, and why its influence has faded. Send all questions to [email protected].