By behavioural psychologists Daniel Kahneman and Amos Tversky in 1973. In their classic experiment, they asked people to listen to a list of names and then recall whether there were more men or women on the list. Some people in the experiment were read a list of famous men and less famous women, while others were read the opposite. Afterwards, when quizzed by the researchers, individuals were more likely to say that there were more of the gender from the group with more famous names. Later researchers have linked this effect to how easily people could retrieve information: we tend to over-rely on what we can remember easily when coming to decisions or judgements.