Why it's better to be 'Plain Jane' than prettiest girl in class

‘Plain Janes' are often happier at school than the girls who seem most popular and attractive because sociable and successful pupils often have the worst problems, said Professor Carrie Paechter, from Goldsmiths College in London.

"There is a lot of pressure to be top of the social group, but often girls who are popular aren't well liked - they're feared because they're dominant," the Daily Mail quoted her as writing in a speech to be given at the Girls' Schools Association annual conference in Liverpool.

Although popular pupils may appear to be part of tight-knit friendship groups, girls who are part of these cliques often turn on each other, as is demonstrated in high school films such as ‘Mean Girls'.

"One group we studied at a school was very dominant and they kept constant surveillance on each other, checking they had their socks rolled down in the exact way and that their hair was done properly," said Professor Paechter, according to The Times.

"There was pressure to be beautiful all the time or you were letting the group down. One of the girls was whispered about because her ponytail wasn't how it should be, and it took her all day to realise what was wrong, then she was mortified.

"Girls further down the pecking order don't notice how their socks should be. If you're being picked on that's awful, but if you're just ordinary you can have a decent time at school, keeping out of it," she explained.

The girls who seem most socially successful can therefore be most at risk of developing emotional or psychological problems, and teachers should react quickly to signs of issues.

Professor Paechter said schools need to support success while reducing what can seem to be a constant pressure to be the best.

Pupils should be encouraged to become aspirational without being perfectionists, she suggested.