I don't know that you needed a scientific study to establish this, exactly.

All Men Watch Porn, Scientists Find | Disinformation:

"Scientists at the University of Montreal launched a search for men who had never looked at pornography – but couldn’t find any.

Researchers were conducting a study comparing the views of men in their 20s who had never been exposed to pornography with regular users.

But their project stumbled at the first hurdle when they failed to find a single man who had not been seen it.

“We started our research seeking men in their 20s who had never consumed pornography,” said Professor Simon Louis Lajeunesse. “We couldn’t find any.”"