The following few paragraphs are from Sociation Today:

Using the work of Elliot (et al. 1996), Gladwell compares the proportion of each class which gets a STEM degree compared to the math SAT at Hartwick College and Harvard University. Here is what he presents for Hartwick:

Students at Hartwick College

STEM Majors | Top Third | Middle Third | Bottom Third |

Math SAT | 569 | 472 | 407 |

STEM degrees | 55.0% | 27.1% | 17.8 |

So the top third of students with the Math SAT as the measure earn over half the science degrees.

What about Harvard? It would be expected that Harvard students would have much higher Math SAT scores and thus the distribution would be quite different. Here are the data for Harvard:

Students at Harvard University

STEM Majors | Top Third | Middle Third | Bottom Third |

Math SAT | 753 | 674 | 581 |

STEM degrees | 53.4% | 31.2% | 15.4% |

Gladwell states the obvious, in italics, “*Harvard has the same distribution of science degrees as Hartwick*,” p. 83.

Using his reference theory of being a big fish in a small pond, Gladwell asked Ms. Sacks what would have happened if she had gone to the University of Maryland and not Brown. She replied, “I’d still be in science,” p. 94.

Gladwell focuses on the fact that the bottom-third at Harvard is the same as the top third at Hartwick. And points to the fact that they graduate at very different rates. It is a fine point. But there is more to the data. The top-third at Harvard have much higher SAT scores than the top-third at Hartwick. Why is it the case that they graduate with a STEM degree at the same rate as the top-third at Hartwick? One answer to that is that STEM degrees at Harvard are harder. So harder coursework at Harvard (vis-a-vis Hartwick) is another explanation for the pattern we see in the data and, in fact, fits the data better as it explains the performance of the top-third at Harvard.

Here’s another way to put the point: If preferences for graduating in STEM are solely and almost deterministically explained by Math SAT scores, like Gladwell implicitly assumes, and the major headwinds are because of relative standing, then we should see a much higher STEM graduation rate for the top-third at Harvard. We should ideally see an intercept shift across schools, which we don’t see, but a common differential between the top and the bottom third.