On diversity: How many is too many, and does it matter?

Calls in support of appointing women as corporate directors have proliferated in recent years: the stated view being that the presence of women around the board table can improve decision quality and, potentially, business performance. Some legislatures have supported these calls by implementing quota systems. Many (but certainly not all) boards now count at least one female amongst their number.

Anecdotal commentaries suggest that the level of attendance, engagement and discussion quality improves after a woman is appointed to a board. This is good, but another question lurks around the corner: If one capable women makes an impact and two more so, is an all-female board better still—or can we have too much of a good thing? Might an all-female board be as problematic as a board comprised only of men?

I've seen some great all-male boards, some great all-female boards and, sadly, some rather ineffective diverse boards in action. That a diverse range of options are explored, independence of thought is displayed and that directors make considered decisions seem to be more important considerations than the physical composition of the board. Thankfully, the rhetoric is starting to mature along these lines. Hopefully director selection processes will soon follow, such that the qualities possessed by directors and the way they work together in the boardroom are the main considerations. Then, the gender (or any other diversity attribute) of directors should matter no more. Might this offer a viable path forward?