The satirical article, Mattel Just Released An Interim CEO Barbie! pokes fun of the precarious and temporary leadership positions that women tend to end up in. The spoof reflects, probably unwittingly, another pattern of women's leadership: The (Interim) CEO Barbie is blonde.

Blonde women are stereotyped as dumb but are disproportionately represented among women leaders in North America. Almost half of the female S&P 500 CEOs are blonde. Over a third of female U.S. Senators (42% of female Canadian Senators) are blonde. These proportions are far above the natural occurrence of blonde hair in North American adults.

 Many firsts in female leadership are also blonde: The first female U.S. Supreme Court Justice, Sandra Day O'Connor; the first female U.S. vice presidential candidate, Geraldine Ferraro; the first serious female U.S. presidential contenders, Hillary Clinton and Carly Fiorina. Even women presidents of prestigious universities are likely to be blonde: Drew Faust at Harvard, Shirley Tilghman at Princeton, Amy Gutmann at the University of Pennsylvania, Susan Hockfield at MIT, Suzanne Fortier at McGill, and Martha Piper at my own university. Look around. The pattern is there.

This first became obvious to me at a conference at the Harvard Business School where the female speakers were mostly blonde. Talking about it with colleagues, it seems there are several potential explanations for this pattern of blonde women being overrepresented among women in leadership. First is racial bias: Blonde hair (and blue eyes) is (naturally) unique to caucasians. Second is attractiveness bias: Blonde women tend to be seen as more attractive, or "sexy," than other women, and, like attractive men, may be more likely than their less attractive counterparts to become leaders. Third is the preference for warmth in women, or the Glinda-the-Good-Witch effect: Blonde women might be assumed to be kinder and gentler than others. Fourth is youth bias: Blonde hair, especially its platinum variety, primarily occurs (naturally) in children, whose hair darkens with age.

Maybe it is all of the above, and women who meet the feminine ideal in North American culture of being white, attractive, young and accommodating are more likely to attain leadership than less "ideal" women, even if these ideals have little to do with (or are seen as inversely related to) competence. My colleagues and I are investigating this seeming paradox of the dumb blonde stereotype and blonde women in leadership. Preliminary results from our first study suggest that, similar to "The Teddy Bear Effect" for black men, in which babyface features render black men less threatening and more warm, innocent and trustworthy, blonde hair may be disarming for women. Our data suggest that blonde women are not only assumed to be younger than their darker haired counterparts, but are also judged to be less independent minded and less willing take a stand than other women and than men. In other words, Barbie can be CEO as long as she is young and/or docile, or being blonde might allow her to be older and more forceful than she otherwise could be.