Image caption Stereotypes evolve and strengthen as they pass from person to person

Stereotypes evolve in a similar way to language, according to research presented at the British Science Festival in Aberdeen.

These generalised perceptions of groups of individuals are an unintentional consequence of information sharing, the scientists claim.

And far from being fixed, they evolve and strengthen as they pass from person to person.

The work was carried out by a team at the University of Aberdeen.

Stereotyping represents a view of other people based on perceptions of a social group and the shared attributes that people within that group are considered to possess.

For example, a typical stereotypical view of salesmen is that they are "confident, talkative and pushy".

To address the genesis of such stereotypes, Dr Doug Martin and colleagues from the University of Aberdeen's Person Perception Lab designed an experiment using aliens - an approach previously used to study the origins and evolution of language.

The aliens they invented each had a different colour, shape and set of personality traits; such as arrogance, pushiness or selfishness.

The team then asked a volunteer to learn the characteristics assigned to each one. The information retained by the volunteer was then fed down a communication chain.

What started out as jumbled and complex individual characteristics and traits ended up encompassed in sets of stereotypes.

Character traits became inextricably linked with form and colour - for example, blue aliens might be perceived as arrogant, pushy and untrusting.

Image caption Pink has not always been the colour associated with boys

As Dr Martin explained: "Information becomes simpler, more structured and more learnable over time" - so much so that the people at the end of the chain were far more knowledgeable than those at the start.

"It's essentially what stereotypes are - massively over-simplified but easily learnable associations between social groups and bits of information," Dr Martin told BBC News.

As the stereotypes evolved, the attributes associated with each group became increasingly polarised.

"It's almost as if at the end of a chain you have the good guys and you have the bad guys", he said.

But are stereotypes fixed? Dr Martin doesn't think so.

"To consider them fixed certainly doesn't represent them fully because stereotypes clearly have changed over time," he said.

According to Dr Martin, the June 1918 edition of Ladies' Home Journal points out "The generally accepted rule is pink for boys and blue for girls…" If true, this is one stereotype that hasn't stood the test of time.

So what will Dr Martin and his team of volunteers - both human and alien - be doing in the future?

"Now we've established that stereotypes can form and change over time via social transmission we now want to see if we can manipulate these," he said.

When asked if stereotypes were an inevitable consequence of society and communication, Dr Martin opined: "We structure the world in a categorical way - it seems our brains are set up to do that.

"People who want to eliminate stereotypes are missing the point."