The researchers say films such as 21 Jump Street (2012), Due Date (2010) and The 40-Year-Old Virgin (2005) have also heralded the era of the ‘Lad flick’ which has made close friendships between men normal and desirable.

All the men involved in the study had had ‘bromantic’ friends who they lived with, and had known for at least 18 months.

Of the 30 men interviewed, 29 said that they had experienced cuddling with a same sex friend, and many said they often slept in the same bed.

One man named ‘Aaron’ told researchers: “We hug when we meet, and we sleep in the same bed when we have sleepovers. Everyone knows it, and nobody is bothered by it because they do it as well.”

Another man surveyed, called ‘Martin’ said: “It’s like having a girlfriend, but then not a girlfriend.

When asked to describe the difference between a ‘bromance’ and a romance, one undergraduate called ‘Bob’ answered: “Sex really. That’s all.”