Tuesday, April 17, 2018

Stemming the Leak

By Fran Bagenal (University of Colorado, Boulder)

How come I hadn’t noticed these facts before? I thought I was pretty much aware of the demographics of women in physics, but the plot below distributed by the American Institute of Physics last spring had me flabbergasted. What has been going on for the past 15 years that has caused the percentage of US bachelors in physics going to women to drop from nearly 24% down below 20%?

The good news is that absolute number of women getting physics degrees (both bachelors and PhDs) are at record values. And the total number of physics degrees, after oscillating around 4000 for the past 50 years, has shot up to 8000/year. Indeed, talking to physics departments around the country I hear reports of bulging enrollments and needs for moving to larger classrooms.

So why is this expansion preferentially male rather than female? Why are men flocking to physics at a proportionally greater rate than women? I fi
nd it very hard to believe that the market for women physicists is saturated and that out of the whole US population only 1550 young women want to study physics.

My guess is that women feel less welcome in larger classes which tend to feel less personal. And, in the sophomore year, when classes revert to “chalk-and-talk” and the homework cranks up, it is easy to become demoralized. Moreover, I’ve noticed that departments often do not put their best teachers in Classical Mechanics I and E&M I. But these are just my guesses.

At UC-Davis they did a study of how students enrolling in different majors migrated over six years to other majors. The plot below highlights Math & Physical Sciences (blue) which shows that only about 20% of incoming students remain in these majors. Why is this happening? Is this also happening at your and my institutions?

These plots have provoked some thoughts of what individuals and departments can do locally to assess their situation and to begin to stem the leak of women from the pipeline.

  1. Most universities have electronic records of student majors, courses, grades and, probably, gender, that could be mined for information about when they switch majors. Departments could employ an interested grad student to track physics majors and find out at what point which students tend to switch. I gather from this paper that women are more likely to switch out of male-dominated STEM majors in response to poor performance compared to men (Kugler et al. 2017). Is this true at your institution?
  2. Physics classes have been evolving over the past couple decades and more interactive engagement in classes, even large lecture classes, have shown major improvement in learning gains (Pollock & Finkelstein 2008). Have the faculty in your department been using these techniques? In upper-level classes as well as introductory levels?
  3. You may have heard that just writing “This test has been designed to be gender neutral” at the top of an exam improves the scores of women in math/physics. A new study went further to show that by affirming one’s values in a couple 15-minute exercises basically equalizes physics exam scores for men and women (Miyake et al. 2010). Yes, I know, this is bizarre. But seems to be scientifically valid. And cheap to implement.
  4. I believe the “sophomore roadbump” is worth working on. Departments are providing study spaces – probably could do with providing more, perhaps in dorms as well as the physics building. How about socializing some spaces with a coffee shop and some music? I like the idea of paying junior/senior physics majors to hang out with the sophomores as “study buddies” – helping them over the roadbump. And teaching the material will likely improve their grades in the physics GRE. If study #1 above confirms my suspicion that sophomore year is when students switch majors, perhaps departments will try to put their star teachers in the sophomore classes.

Indeed, it would be great if society were a less gender biased in its portrayal of physicists (e.g. type physicist into Google image search). But such things are hard to change. We can at least do our own research in our own departments and act locally to stem the local leaks from the physics pipeline.


Kugler, Adriana D., Catherine H. Tinsley, Olga Ukhaneva, Choice of Majors: Are Women Really Different from Men? NBER Working Paper No. 23735, DOI: 10.3386/w23735, 2017, http://www.nber.org/papers/w23735

Miyake, Akira, Lauren E. Kost-Smith, Noah D. Finkelstein, Steven J. Pollock, Geoffrey L. Cohen, Tiffany A. Ito, Reducing the Gender Achievement Gap in College Science: A Classroom Study of Values Affirmation, Science, 330, 1234-1237, DOI: 10.1126/science.1195996

Pollock, S. J., N. D. Finkelstein, Phys. Rev. Spec. Top. Phys. Ed. Res. 4, 010110, 2008, DOI: 10.1103/PhysRevSTPER.4.010110