Jake Gyllenhaal believes people are controlled by the moon.

The 'Southpaw' actor thinks it is ''natural'' that lunar cycles impact on human behaviour because the body is made up of a high percentage of water.

He said: ''I believe deeply in the unconscious. That you literally accumulate the molecules of the space that you're in. We're like 90 per cent water, so naturally we are going to be affected by the moon when it's full: if the sea is, why wouldn't we be? That seems scientific to me.''

And the 34-year-old actor - who spent six months with police researching his 'End of Watch' character - believes immersing himself into the roles as thoroughly as possible translates to a better performance because he has the ''molecules'' of the situation ''transferring'' to him.

He explained in an interview with Esquire magazine: ''So, if you spend enough time in whatever environment your character would exist in - the way I spent six months with police officers - then the molecules of that environment must transfer somehow. And then you put it on screen, and people go, 'I feel something that I don't normally feel.'''

Jake admits there were times when he was training with the police that he wondered if he had taken his research too far, but had an ''amazing'' experience and it changed his life.

He said: ''There were times, when I was taking cover, wearing a Kevlar vest and thinking, 'Come on, we're making a movie!' You know?

''I have never felt so good about being in Los Angeles as when I was in East LA working with police officers. Just being in that culture, especially the Hispanic culture. It was amazing.''''