Millenials are narcissistic, scientists are geeky, and men like sports - or so cultural stereotypes would have us believe.
Regardless of whether we believe them to be true, we all have extensive knowledge of cultural stereotypes. But how does this information become associated with certain groups in the first place?
Research published in Psychological Science, a journal of the Association for Psychological Science, suggests that cultural stereotypes are the unintended but inevitable consequence of sharing social information.
"We examined how social information evolves when it is repeatedly passed from person to person," explained psychological scientist Doug Martin, who leads the Person Perception Laboratory at the University of Aberdeen. "As it passes down a chain of individuals, social information that is initially random complex and very difficult to remember becomes a simple system of category stereotypes that can be learned easily."
According to Martin and colleagues, stereotypes may have negative consequences when they contribute to prejudice, but they can also help us make sense of the world around us, helping us in "the way we organize, store, and use information about other people."
"For example, if we meet a stranger, stereotypes provide us with a foundation on which we can begin to build an impression of this person and therefore guide our behaviour towards them," says Martin.
Martin and colleagues conducted lab experiments in which they asked people to remember information about novel alien characters and then pass this information from person to person. Like the game "Telephone," they expected the information to change as it travelled down the chain of people.
Volunteers were asked to learn personality attributes that described the aliens, all of whom shared certain physical features such as their color, their shape, or the way they moved.
Each person was then tested to see what they could remember. Whatever information they produced was then passed on to be learned by the next volunteer and so on until a chain of information was created.
"As information is passed from person to person, what begins as a chaotic and random association of aliens and attributes becomes simpler, more structured and easier to learn," says Martin. "By the end of the chain we have what look very much like stereotypes with physical features - such as color - strongly associated with the possession of specific personality attributes."
The researchers say stereotypes appear to form and evolve because people share similar cognitive limitations and biases.
People are more likely to confuse the identity of individuals when they belong to the same social category than when they belong to different categories. Similarly, people are more likely to mistakenly think that individuals who belong to the same social category also share the same attributes. Because we all experience the same category-based memory biases, when social information is repeatedly shared it is continually filtered as it passes from one mind to the next until eventually it becomes organised categorically and a stereotype has formed.
The scientists say their research appears to explain why some stereotypes have a basis in reality while others have no obvious origin.
"For example, the cultural stereotype of Scottish people includes attributes that are overrepresented among Scots, such as wearing kilts and having red hair, but also attributes that seemingly have no basis in reality, such as being miserly or dour," says Martin.
"Where a genuine relationship exists between social categories and attributes, people are very good at detecting this, remembering it and then passing this information on. Equally, however, where there is no existing relationship between social categories and attributes, we see this association emerging spontaneously over time as the social information evolves," Martin explains. "If we can understand how cultural stereotypes form and naturally evolve then we might be able to positively influence their content in the future."