A 2012 research project published in the American Political Science Review conducted at Brigham Young University and Princeton examined "whether women speak less than men when a group collaborates to solve a problem." In the majority of groups that these scholars studied women were significantly less engaged than their male counterparts. The study concluded, that the amount of time women contributed to the discussion was significantly less than their actual representation in the group. Women were verbally engaged 75 percent of the time vs. their male counterparts .
While the above research concluded that women don't speak up in groups dominated by their male counterparts women do tend to talk more in certain settings.