You really don't.
This is what I would define as "weak," which is why I believe we simply have different perceptions around such a term. I don't mean it in a derogatory sense, of course. The minds of women are "weak" in the sense that they are susceptible to the errors that can come from this "groupthink" at a rate higher than men, as you've pointed out. This is why I have said that it is, then, easier to forgive them, for they are naturally disposed to that behavior at this higher rate.
That they are "weak" isn't to say that they are retarded or otherwise incapable of complex, intellectual thought, however. Rather, it is that such intellectual thought in a woman's mind has a more delicate foundation than the minds of men, so the minds of women can get flipped around and fiddled with more easily. Think of lighter and heavier ships on the open sea. It isn't the best analogy, but it explains the relationship well.
With lighter ones, you can travel quickly and in efficient groups, yet they are susceptible to the hefty waves that push them around easily on the sea. With something heavier, like a galleon, you have a stabler course, but travel is going to take a long while. Either have their benefits. Like I once read from a holy man who was writing on the topic of marriage and the differences in the minds of men and women, the "gas and brakes" that are the two sexes are both necessary for structure to exist in mankind.