Four top biases
Four common ways our brains trick us into making false assumptions

1. Stereotyping: oversimplified and misleading beliefs about the habits or characteristics of a certain group of people. ‘Only males play video games’ is a commonly encountered stereotype, but in fact nearly half of video gamers are women.

2. Confirmation bias: favouring information that confirms preconceived beliefs. If someone believes that left-handed people are more creative, for example, every creative left-hander they encounter is proof, whereas they are likely to regard creative right-handers as exceptions that can be ignored.

3. Halo effect: using a single physical or personality trait to form an overall judgment of that individual. So an attractive or well-dressed person is more likely to be perceived as honest, hardworking and trustworthy than someone less attractive or untidily dressed.

4. Like me effect: the tendency to favour people who are most like us. So when recruiting we may prefer candidates with similar — rather than different — backgrounds, interests or education to our own.