Comment It starts before school. About 15 years ago, I (Score 1) 493
started a STEM program to fill the second half of the day for half-day kindergartners, in four affluent suburbs. "Great!" thought I - this is a chance to get these kiddos before school had a chance to socialize them into well-known STEM gender roles. They haven't been to school yet (plus or minus the odd day care setting - but still nothing like being in school 6hours per day for 180 days for X number of years. Clearly this is as close to tabula rasa I'm going to get for schooling.
Surprise, surprise surprise. 90% boys enrolled. Ads, flyers all gender neutral or balanced images. Every year I'd survey the parents, the most common response about female sibs was that no, I'm putting "her" into (dance / swimming / skating / etc.), she's not really into that science-y stuff. Uh huh. The kid just came up with that? Sorry folks, waiting to middle school to fix this is shoveling against the tide. We learned the value of "early" and the value of prior knowledge as an entry point way back with LEGO TC Logo.