[on the character Jason Voorhees, whom he plays in Friday the 13th (2009)]: For the mental aspect of it, I did a lot of research on child-development. In the script, Jason loses his mother and sees her get killed in front of him. He was nine to ten years old when that happened. So I did research on, when you're that age how do your cognitive processes happen? How is the child supposed to be developing? I found out that at that age you're starting to be integrating into society, whether it's through group sports or group activities so that you find out you're not alone. I discovered that he missed that aspect. He was already an outcast from society for looking different and being disfigured, and his only connection to love and reality is his mother. Losing her, he never got the chance to be a team player. I explored the psychological aspects of that and different parts about serial killers -- at some point something traumatic happens in their younger lives that makes it happen, or makes them not think clearly like everyone else.