Scientists used an algorithm to apply the Bechdel test to real-life conversations via the social media platform Twitter and to relate these to the gender bias of movies.
The Bechdel Test, developed by US cartoonist Alison Bechdel in 1985, shows whether a movie features a minimum of female independence.
Researchers chose Twitter users from the US who shared the link to a movie trailer on YouTube over the course of six days in June 2013, plus the users who interacted with them over a longer period of time.
They analysed the roughly 300 million tweets like a gigantic movie script with 170,000 characters to compute an interaction network.
"I expected that on Twitter men would mention women in their conversations as often as women mentioned men," said David Garcia, researcher at the Chair of Systems Design at ETH Zurich.
The analysis revealed a different picture: Twitter conversations among men featured fewer mentions of women.
In turn, there were more conversations between female Twitter users that contained references to men than conversations without a male reference.
However, the researchers did not find such a male bias in all Twitter users. The conversations of students proved to be more balanced regarding references to the respective other gender.
In contrast, the tweets of fathers were even more male-biased: they interacted even less with female users and mentioned women even less often than childless men.
"Possibly this is because fathers tend to be married while men without children may be married or single," Garcia said.
Those Twitter users whose conversations passed the Bechdel test also tended to share the trailers of movies that also passed the test.
In general, the trailers of such movies were shared less often via Twitter and received fewer positive ratings on YouTube than movies with a male bias, meaning they had fewer fans.
"It appears that Twitter is more male-biased," said Garcia.
In comparison, conversations via Myspace, another social network, displayed less of a gender bias than those on Twitter, probably because conversations are more private on Myspace.
Garcia's algorithm could serve as a tool not only to rate movies in which one of the genders is underrepresented, but also to analyse the design of social networks.