Are you good or evil? - click here

BBC: Can the warrior gene make you violent? - click here

The Krays - click here

Tinbergen’s Experiment - click here

Why domestic violence victims don’t leave - click here

The Brain: A Secret History - Emotions; Bandura Bobo Doll Experiment - click here

Real stories: Nature over nurture? The Coronation Street Killer - click here

Real stories: Unforgiven: The Tragedy of James Bulger and His Killer Boys - click here