According to a study conducted at the University of Colorado Boulder, when there’s only one woman in a candidate pool, there’s little chance she will be selected. Her chances greatly improve — far more than the increased statistical chance — when the number of female candidates increases.
In an article in the Washington Post, writer Jena McGregor applies the principle to politics, but the main evidence relates to business hiring. One of the professors involved in the study explains that the relevant concept is “tokenism”: When there’s one woman in a group of men, she is often seen as being representative of all women.
The professor, Stefanie Johnson, adds, “When you have at least two women, you realize those women are going to be different from each other…You can’t apply the stereotypes in the same way — it doesn’t make sense.”
The article also cites other research finding that “on corporate boards, it’s not until there’s three women in the room before their contributions make the most impact, rather than being seen as representing a woman’s view.”