Not being sarcastic, is there evidence that more diverse teams are better? There seems to be some anecdotal evidence going both ways (i.e. more diverse viewpoints vs team cohesion). I can imagine that there's a balance point as well. You could have one extreme where people are so similar that its basically a one-person team with 8 arms. You could also have a team so diverse they can never agree, have no common language and no shared cultural aspects, or even shared goals. An interesting balancing act really.
The authors did indeed find a balance point, at about 50:50 (a far cry from the 81:19 among engineers at Google). OTOH, this was for a very different kind of task than programming. Another starting point is here:
It's particularly interesting that many summaries of this work will use vague terms like "composition of the group" to avoid mentioning anything in the findings about number of women in the group.
