Interesting events I see: "October 11 – Aboard the Space Shuttle Challenger, astronaut Kathryn D. Sullivan becomes the first American woman to perform a space walk." - Wikipedia. Not sure how that'd inspire CS only, though. Also: "April 23 – Margaret Heckler of the U.S. Public Health Service announces the identity of HTLV-III as the virus that causes AIDS."

See this article.

@heather thank you for the article. The conclusion seems to be: assume that students in intro courses have no experience. Sounds good. I don't recall having a bias when I was a TA for an intro class 30 years ago. If anything, women learned faster and with more clarity. Men were simply more persistent in some cases (pig-headed, actually).

Enrollment generally declined after 1984. The problem is that it rose later for (only) men. So, 1984 isn't the year to focus on, but a bit later. What happened then?

Here's a link to the data with absolute numbers, which are actually quite interesting and illustrate the significant decline in total enrollment after 1984 that Buffy mentions. To put the numbers in some context, the absolute number of degrees across all fields for 2010-2011 is show here.

The gender disparity isn't about unequal opportunity but unequal desire; women can be computer scientists, it's just that, given the choice, they disproportionately prefer being doctors instead. Educators should focus on empowering to students to make decisions that they're happy about. Beyond that, it should be all about free choice.

@Buffy but the plot is about %, so a decrease in the absolute number of enrolments should not have affected it, unless it decreased faster for women, hence it is still worth investigating

@heather: "Not sure how that'd inspire CS only, though." Similarly, I would expect e.g. Michael Schumacher's skill and fame to have had an influence on how many people enrolled to become a mechanic. The auxiliary jobs (developer/mechanic) usually far outnumber the "hero" jobs (astronaut/F1 pilot), and not everyone thinks of themselves as a "hero in training". Engineering was on the rise at the same time as CS, arguably also related to "hero" astronauts. The larger rise in CS may be influenced by the general increase in computer technology (and need for workers) at the time.

I'd also say that a lot more are going into (software) engineering as well

Most of these comments do not address the sudden drop after 1984.

@EllenSpertus If I may chime in. Looking at some of the links here, the decline of degrees doesn't necessarily seem to be a gendered issue. One of the links posted, indicates that the ratio of women:men stays relatively stable until 2005 or so.

@nobrandheroes While you're right that enrollment went down for both men and women, it's well documented that it went down by a larger percent for women than for men. What link suggests otherwise?

It's not only a peak at 1984, but also a steep decline after 2000, similarly steep than the decline after 1984.

A very simple explanation - males started doing CS in very large numbers after that year. The % dropping doesn't mean less females were on the field, just that the proportion of males to females changed.

It would be very interesting to see that "medical professions" line separated out a bit more