Why aren't there more women in the upper echelons of science? It's a question with many answers, but John Tierney at the New York Times is only interested in one: Maybe women just aren't smart enough. 

In two columns (on June 8 and June 15) for the New York Times, Tierney argues that men outnumber women at the extreme ends of the intelligence bell curve. Though the sexes may cluster around the same average intelligence, men are more likely to occupy the very highest (and lowest) percentiles in tests of mathematical ability. Maybe this, not gender bias, is the invisible force holding up science's glass ceiling.

Here's why we think Tierney is wrong.

• Most women just starting their science careers don't face the kind of brazen discrimination their predecessors did. Thank goodness for that. Yet there is good evidence that implicit biases color the way we think about girls' capacity to do science. Both women and men are vulnerable to these biases, and they can be self-fulfilling: "Stereotype threat" can cause some women to underperform when they are told to expect that their gender will negatively affect their performance on a test.

• How can we untangle these social influences from innate ability? One way might be to check whether the math score gender gap persists in other cultures. In fact, it doesn't. More to the point, when the gender gap is matched up with measures of implicit bias, the gender gap widens and narrows in perfect harmony with the strength of a nation's implicit biases. 

• But let's imagine that the gender gap is real. Is exceptional performance on a math test really a good predictor of an individual's promise as a scientist anyway? The best scientists also have to be top-notch communicators, They have to spread excitement about their ideas at conferences and lectures, and they have to write persuasive grant proposals. They have to manage teams of students and post-docs. And they need a creative spark that sets them apart. One math score is a paltry proxy for this multifaceted set of skills.

• There is good evidence that male and female brains do process information differently. But that's not a bad thing. In fact, science can only benefit from the participation of minds that literally "think differently." Novel approaches and new ways of seeing problems are responsible for great leaps in science and technology.

• Finally, what's the point? Science has tremendous potential to help our society face its challenges, so let's ask whether this debate is really a constructive one. Most scientists, smart as they may be, do not occupy that coveted space at the very end of the bell curve. And yet they do good and important work. Why exclude 50% of the population from even trying? What message does that send to girls and women--as well as men who might not occupy that far-right tail on the bell curve--considering careers in science?

 At NOVA and NOVA scienceNOW, we are proud to introduce viewers to scientists of every gender, race, nationality, and age. (See some recent examples of scientists of all types at our Secret Life of Scientists and Engineers series.) These are people of remarkable intelligence but also exceptional dedication, passion, and creativity. We hope that by presenting these scientific role models, we can encourage would-be scientists of every shape, size, and color to pursue their passion. Anything less does a disservice to science and the society it serves.