A behavioural expert believes the team behind One Direction might be pushing them too hard.

The boyband are stuck in a constant cycle of touring and recording, and whilst they seem to be enjoying their success, it could take its toll.

Expert on behaviour Judi James believes One Direction's management are "absolutely milking them dry" and that the band's happiness could suffer as a result. She told Entertainmentwise:

"They look very positive at the moment, they're clearly just enjoying it, but if it goes on for too long that sort of pressure can be wearing."

James added that the interest in their private lives and their rabid following means that they are often cooped up inside. She said:

"They're healthy guys kept prisoner in hotel rooms."