Andy Serkis studied world leaders before playing alpha male ape Caesar in Dawn of The Planet of the Apes.
The 50-year-old actor played the primate leader in the science fiction movie and revealed he took inspiration for the part from real presidents.
He said: ''When I started playing Caesar I did quite a lot of research into chimpanzee behaviour but actually what was imperative understanding that Caesar is a human trapped in an ape's body.
''With Dawn of the Planet of the Apes I studied world leaders and the decisions that they have to make and how they often make the wrong decisions but admitting they make the wrong decisions. All the psychological questions.''
Serkis also admitted he hopes the emotional connection with the characters makes people reflect on their own behaviour, adding, ''It's like saying all humans are the same. That's the point, these films are more about investigating ourselves.
"Emotionally you can relate to these characters even though they are another species. The level of reality in this is much more human because he is becoming more human from Rise when he was much more ape-like.''
