<p>The factors cited here as lowering the grad student IQ average have, if anything, a stronger negative effect on the undergrad population IQ at Harvard. </p>
<p>To take some examples from above:</p>
<p>— undergrads who don’t enter grad school within 5-6 years of graduation may include some who have amazing business options due to their brilliance, but for every one of those, there are several Harvard undergrads whose grades, ambitions and talents (or lack thereof) support neither a grad-school application nor appetizing job prospects. That is, the population of “grad school avoiders” oversamples the bottom of the spectrum, just as the population of PhD students at Harvard oversamples the top.</p>
<p>— weak PhD departments tend to be weak undergrad departments, except that they are often larger at undergrad level. There are many more English majors in proportion to undergrad than at PhD level, because funding is scarce for comparative literature and poetry compared to engineering. </p>
<p>— some departments do indeed rely on lab work and recommendations to admit students, more so than IQ surrogates per se. However, this is also true for the undergrad population, where credentials including lab work and recommendation letters (not to mention evidence of work ability such as grades and “class rank”) are far less discriminating and IQ-loaded than for the grad students. What mollyB forgets is that those PhD lab slaves in biochemistry, chemistry, etc had to pass IQ-loaded filters such as getting good grades in Orgo and Physical Chemistry in order to be live candidates for admission, which again puts them ahead of the lower 30 percent of Harvard undergrads (or 50 or 20, it doesn’t change the conclusion).</p>
<p>— the international pool is far stronger at grad level than undergrad, for obvious reasons. Over and above the usual litany, let me also note that of the 8-9 percent of “international” students at undergrad level, 20-25 per cent are from Canada and a similar share are from American international schools abroad, schools for diplomats and similar admission paths that are no harder than the domestic US admissions. Relatively few of the internationals at undergrad level at Harvard come from the hypercompetitive brilliant-and-hungry pool that populate the PhD programs later on.</p>
<p>The list can be continued. The bottom line is, again, that:</p>
<p>PhD admission oversamples the top of the undergrad IQ spectrum and undersamples the bottom, and the same is true for selecting tenured faculty from those with PhD’s.</p>