From the Office for diversity initiative at Columbia University:

Social psychology research has found that both men and women are more likely to hire a male applicant than a female applicant with an identical record (Steinpres et al., 1999).

Deaux & Emswiller (1974) found that success is more frequently attributed to “skill” for males and “luck” for females, even when the evaluators are presented with evidence of equal success for both genders.

Beginning in the 1970s symphony orchestras started requiring musicians to audition behind screens; since that time, the number of women hired has increased fivefold and the probability that a woman will advance from preliminary rounds has increased by 50% (Goldin and Rouse, 2000).

I first read about the fivefold increase in hired female musicians after the introduction of blind auditions in the insightful book by Malcolm Gladwell “Blink: The Power of Thinking Without Thinking” and reminded about it by a recent study on 300.000 twitter users by Bill Heil (billheil @ twitter) and Mikolaj Piskorski (mpiskorski @ twitter).

Although men and women follow a similar number of Twitter users, men have 15% more followers than women. Men also have more reciprocated relationships, in which two users follow each other. This “follower split” suggests that women are driven less by followers than men, or have more stringent thresholds for reciprocating relationships.

This is intriguing, especially given that females hold a slight majority on Twitter: we found that men comprise 45% of Twitter users, while women represent 55%. To get this figure, we cross-referenced users’ “real names” against a database of 40,000 strongly gendered names.

Even more interesting is who follows whom. We found that an average man is almost twice more likely to follow another man than a woman. Similarly, an average woman is 25% more likely to follow a man than a woman.

Finally, an average man is 40% more likely to be followed by another man than by a woman. These results cannot be explained by different tweeting activity – both men and women tweet at the same rate.

These results are stunning given what previous research has found in the context of online social networks. On a typical online social network, most of the activity is focused around women – men follow content produced by women they do and do not know, and women follow content produced by women they know.