It’s rare for a woman to make it to the very top of a large corporation these days, and it’s rare for an adult human to have blond hair. But blond women are far more likely to end up a chief executive or U.S. senator than women with any other color hair, according to recent research from two business-school professors at the University of British Columbia.

Just 2 percent of the world’s population and 5 percent of white people in the U.S. have blond hair, but 35 percent of female U.S. senators and 48 percent of female CEOs at S&P 500 companies are blond. Female university presidents are more likely to be blond, too.

Jennifer Berdahl and Natalya Alonso, who presented their research at the Academy of Management’s annual meeting early this month, say some of this blond overrepresentation can be explained by race and age biases in leadership pipelines. Blond hair is primarily found in white people, and white people take up a disproportionate amount of space in the top tiers of business and politics, so it makes sense that there are a disproportionate number of blondes. And children are more likely to be blond than adults, meaning the trait signals youthfulness. But whatever blond privilege may exist in the upper echelons of power, it doesn’t apply to men: A study published in 2005 revealed that just over 2 percent of male Fortune 500 CEOs were blond.

There would seem to be a paradox between the age-old stereotype of the dumb blonde and this preference for blondes in leadership positions. But on her blog, Berdahl suggests that the two concepts aren’t so contradictory after all—the dumb blonde paradigm might actually explain blond overrepresentation. “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,” she writes. “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.”

Of course, many women—especially those around the age of the average CEO or senator—dye their hair, so there are far more people with blond-looking hair than naturally occurs. Still, that dyed proportion wouldn’t come close to accounting for one in three female senators or one in two female CEOs being blonde. Berdahl told the Huffington Post that a beefed-up dyed-blonde population would do more to support her conclusions than disprove them. “If women are choosing to dye their hair blonde, there’s something strategic about the choice,” she said. “If the package is feminine, disarming and childlike, you can get away with more assertive, independent and [stereotypically] masculine behavior.”

In their research, Berdahl and Alonso got 100 men to rate photos of blond and brunette women on attractiveness, competence, and independence. The two groups of women scored equally on the first measure, but blondes fared worse on the latter two. Then, the men were shown photos of the same woman with blond hair and brown hair. The majority chose to recommend the brunette over the blonde for a job as a CEO or senator. But when the men had to rate dominant-sounding female leaders—photos of the same woman with blond or brown hair, paired with quotes like “My staff knows who the boss is”—they thought the blond woman was warmer and more attractive than her brunette twin. Berdahl’s blog calls this “the Glinda-the-Good-Witch effect.”

The conclusion of these studies—that people are better able to stomach a female leader if they perceive her to be gentler, less demanding, and weaker-willed than her dark- or gray-haired peers—aligns with earlier research on black men in positions of power. A study published in 2009 found that black male Fortune 500 CEOs were more likely to have baby-faced traits (a round face, large forehead, and smaller nose) than their peer CEOs, while a previous study showed that white men are less likely to make it to top spots in business if they had those traits. Researchers posited that people felt more comfortable with a black man in charge if he had a “disarming,” “nonthreatening” appearance. White men seem to be the only ones who can’t look or act too threatening for their positions of power, probably because we’re used to seeing them there. If someone says “my staff knows who the boss is,” I’d usually guess it’s the white guy.