Petrie multiplier

The Petrie Multiplier is a thought experiment by Karen Petrie that reveals that a minority of women in a group will experience a disproportionate amount of sexist interactions even if men and women in the group are equally sexist. This effect was named and popularized by Ian Gent who explained that if there are four times as many men in a group "there are 4 times as many men to make sexist remarks, so 4 times as many sexist remarks are made to women as to men." There are also four times fewer women to receive those sexist remarks so "the mean number of sexist remarks per woman is 16 times the number per man. This holds in general, so with a gender ratio of 1:r, women will receive r² times as many sexist remarks as men". The importance of the Petrie multiplier is that it shows how women can correctly perceive that women are insulted more frequently in technology, without it being necessary that men are in general more sexist than women.

The multiplier effect is identical to that operating in Lanchester's laws, where its cumulative attritional effect over time is known as the "square law".

Illustration

Illustration of the Petrie Multiplier. This is an animated gif in which the action is played only once, ending at the final situation.

The image shows an animation of the Petrie Multiplier.

Criticisms of the Petrie Multiplier

Some analyses of the Petrie Multiplier have suggested the original model is too simple to accurately model social interactions. However, both of these studies, using more advanced models, showed the same underlying issue, and in fact in both cases showed the Petrie Multiplier understated the problem (that is, we would expect to see the minority group have a much worse time than the original Petrie Multiplier would suggest).