the study zeroed in on a unique situation — an unnamed Boston professional services company with 60 small offices around the world, some of which were staffed entirely by men, some made up of only women. Using employee surveys from 1995 to 2002, the researchers measured cooperation, trust, and work enjoyment, along with corresponding figures on diversity and revenue over that same eight-year period.The research showed that while the diverse offices were on average more productive, the people in them were less happy and less trusting. Men were happier in all male offices, women in all female offices. Women complained that men don't take them seriously and monopolize all the attention, while men complain that with women around they have to constantly monitor what they say -- "walk on eggshells", as one put it.
Obviously this is just one study, but I think it gets at something important. Single sex groups are different from mixed groups. Most of the time I prefer to be in a mixed setting, because all male groups tend toward locker room coarseness. But because I recognize that all male groups have a different feel, I certainly believe that some men prefer them. In our world we have been working to break down every gender barrier we can find, and one result has been the decline of those all-male clubs that used to be such a big part of many men's lives -- the Elks, the Shriners, etc.
Societies vary a great deal in how much time men and women spend together. In some, both spend most of their time in all male or all female groups. (Or for women, all female except for male children.) In others, men and women do many things together. Over the past century, single sex space in our society has shrunk, and mixing has increased. In general I think this is a good thing, but it has a high cost for women who are more comfortable around other women, and men who prefer to be around men.