Kanye West is wrong – it's cool to smile

That's according to researchers in the US who challenged the idea that concealing emotions was perceived as cool.

This message is reinforced through advertisements where fashion models rarely smile and by quotes from celebrities.

In an article in the Huffington Post, Kanye West said he doesn't smile in photographs because 'it just wouldn't look as cool'.

In a series of experiments, researchers at the University of Arizona showed participants photographs of celebrities and non-celebrities who were smiling or inexpressive, and their results call into question common assumptions about what makes someone cool.

They reveal: 'We found over and over again that people are perceived to be cooler when they smile compared to when they are inexpressive in print advertisements. Being inexpressive makes people seem unfriendly or cold rather than cool.'