A study, published in Current Biology, saw researchers examine personality characteristics and eye colouration in people of North European ancestry.

And, their analysis says that people with lighter eyes are more likely to be “egocentric, competitive and sceptical” – while people with darker eyes are apparently more “agreeable”.

Scientists believe that this may have something to do with our evolutionary roots: thousands of years ago, our Northern European ancestors found light-coloured eyes more attractive. Thus, it's possible that blue-eyed people ended up having more of a competitive edge in this geographical area as blue eyes were rarer.

As they explain in the paper, “The rare-colour advantage of light-eyed females is likely to increase the chance of being noticed by a male.

“Moreover, competitive personality traits (such as wanting to beat others and being sceptical of others’ intentions) secure the long-term commitment necessary for self and offspring survival.”

People with blue eyes share this personality trait, according to science