The precipitous drop in American science students has been visible for years. In 1998 the House released a national science-policy report, "Unlocking Our Future," that fussily described "a serious incongruity between the perceived utility of a degree in science and engineering by potential students and the present and future need for those with training."
Let me offer a different explanation. Students respond more profoundly to cultural imperatives than to market forces. In the United States, students are insulated from the commercial market's demand for their knowledge and skills. That market lies a long way off -- often too far to see. But they are not insulated one bit from the worldview promoted by their teachers, textbooks, and entertainment. From those sources, students pick up attitudes, motivations, and a lively sense of what life is about. School has always been as much about learning the ropes as it is about learning the rotes. We do, however, have some new ropes, and they aren't very science-friendly. Rather, they lead students who look upon the difficulties of pursuing science to ask, "Why bother?"
Success in the sciences unquestionably takes a lot of hard work, sustained over many years. Students usually have to catch the science bug in grade school and stick with it to develop the competencies in math and the mastery of complex theories they need to progress up the ladder. Those who succeed at the level where they can eventually pursue graduate degrees must have not only abundant intellectual talent but also a powerful interest in sticking to a long course of cumulative study. A century ago, Max Weber wrote of "Science as a Vocation," and, indeed, students need to feel something like a calling for science to surmount the numerous obstacles on the way to an advanced degree.
At least on the emotional level, contemporary American education sides with the obstacles. It begins by treating children as psychologically fragile beings who will fail to learn -- and worse, fail to develop as "whole persons" -- if not constantly praised. The self-esteem movement may have its merits, but preparing students for arduous intellectual ascents aren't among them. What the movement most commonly yields is a surfeit of college freshmen who "feel good" about themselves for no discernible reason and who grossly overrate their meager attainments.
Later in the article, by the way, Wood refers in passing to Larry Summers' exit as president of Harvard--"pushed out ... for speculating (in league with a great deal of neurological evidence) that innate difference might have something to do with the disparity in numbers of men and women at the highest levels of [the sciences]". This reminds me to link belatedly to a recent post by Alex Tabarrok: "Summers Vindicated (Again)". A new study of the mathematical ability of boys and girls has been widely reported as finding no difference between boys' ability and girls'. I remember thinking, as I skimmed some of those reports, that Larry would have to revise his opinion. Obviously I should have smelled a rat. Alex explains that the reports were wrong, and the study in question (despite its title, and the evidently successful efforts of the authors to downplay the fact) actually bears out what Larry said. A revealing episode in more ways than one.