Quantic Foundry, an organization that studies gamers, conducted a survey where they asked gamers to rate their enjoyment of different forms of social gameplay. They were specifically interested in how people enjoyed local co-op with friends, co-op with friends and family online, co-op with strangers online, local competitive play with friends, competitive play with friends and family online, and competitive play with strangers online.
1,266 people participated in the survey, and they found that while playing with friends, co-op is more enjoyable than competitive play. They also found, that along gender lines, co-op is equally enjoyed by men and women. But while women and men both equally enjoy completely co-op games, no matter if they are in the same room or online, once the game has a competitive aspect, women rate their enjoyment of those games lower than men rate them. So even though games like Overwatch and League of Legends are team based, because they are competitive, women say they enjoy them less.
As for gaming with strangers, everyone rated that kind of co-op, regardless of if it is completely co-op or with a competitive aspect, as the least enjoyable kind of co-op gaming. The rating makes total sense, because often times a team-based competitive game like Overwatch usually requires at least some level of coordination to win, so if you get paired with a bad group, your experience of the game suffers.
Even more significantly, this study found that women rated team-based competitive play with strangers way lower than men. So not only do they rate competitive play in general as less enjoyable than their male counterparts rate it, but once it involves strangers, the enjoyment gender gap widens significantly. Most gamers could have probably predicted this particular result, considering that it has been widely talked that gaming communities can be abusive and hostile towards female gamers.
The study concludes that the local co-op game is a great market for developers, because it is equally enjoyed by both genders, and is rated as the most enjoyable form of co-op games.