Many years ago, I learned the so-called “Golden Rule” of biochemistry: You get what you assay for. In other words, the result you attain from an experiment depends upon what you measure. This is a basic lesson and a good one, one that college admissions staff would do well to remember.

Harvard’s retreat from Early Decision this fall has called public attention to a larger problem in college admissions: With the twin goals of enrolling better students and climbing in the rankings, colleges have quietly morphed into high-throughput sorting machines, judging applicants very efficiently on questionable criteria.

Earning a spot at a top school has become quite the undertaking indeed. We’ve all met students who stacked their extracurricular dance cards from an early age, and others whose devotion to high school volunteerism was perhaps not entirely selfless. We know those who studied fanatically for standardized tests, and we’ve all heard of high-priced admissions experts grooming applicants for an Ivy nod. In a world where everything can be gamed, what pure metrics remain?

Admissions committees employ a few key measures to assess academic ability, intellectual promise, community dedication and whatever else. But the playing field is tilted, favoring those with the time and money to boost their scores, hire essay advisors and otherwise whack every mole. An applicant who cannot afford such luxuries is effectively consigned to a lower percentile rank by the many thousands who can.

I had a recent brush with this phenomenon last December, when I decided to apply to law school. Clueless, bigheaded or both, I took the LSAT pretty much cold. My thinking was that because the exam is designed to test not rote knowledge but some vague idea of general aptitude, little would be gained by studying. As the hordes now gearing up for the September sitting will no doubt attest, this was a trifle optimistic.

Since taking the exam, I’ve spoken with a good number of people at the other end of the spectrum: those who spent many months drilling questions, shelled out a small fortune for LSAT courses, rehearsed every possible type of logic game and predictably did exceptionally well — far better than their initial timed diagnostic. It’s not a miracle cure, but dedicated preparation undoubtedly boosts test scores. Many prep courses guarantee it.

If standardized tests can be gamed — even a little — by those with time and money to devote to extensive preparation, they’re not the great equalizer we think they are.

Sifting through such inequalities is the job of admissions committees, and they’re surely very good at it. The whole problem might end right there, if the committee’s freedom to assemble a class were not curbed by outside pressure.

Perhaps more than any other single factor, reliance on the U.S. News and World Report college rankings has polluted the admissions process. By evaluating every college with the same superficial criteria, trumpeting the result as the one true barometer of academic quality and convincing society to buy into it all, this publication has irrevocably damaged the academic landscape in the United States.

Rankings are mostly harmless until colleges heed them. Once schools begin altering their admissions behavior to improve their standing, a feedback loop is formed. The driving force in admissions is no longer just assembling the best possible class; it is now to assemble the best class that will also look the best on paper.

The problem with this is that by amassing aggregate values, rankings cannot help but de-contextualize any information they present. This encourages schools themselves to divorce standardized test scores from the remainder of an applicant’s package and apply cutoffs and absolute limits — an approach that doesn’t make sense given the basic intent of the tests.

Test scores matter, in an absolute sense, because rankings pressure schools to court and enroll the highest-scoring students. A pricey game can be played to boost test scores. Some, constrained by job, family or finance, can’t afford to play.

This is the very same inequality that eventually condemned early decision, a process that compels applicants to commit to a school before seeing its financial aid offer. Harvard’s move will be widely copied, and this is a good thing: Doing so removes one barrier from a system that has become increasingly geared toward high-income applicants.

As good meritocratic citizens, we rightly reject the notion that a privileged upbringing should sway an admissions panel. But remember the Golden Rule: If we define aptitude as the ability to cram all summer and game an exam on daddy’s nickel, then sorting applicants by standardized test score will indeed select for very apt people. Anyone with a summer job or bills to pay is just out of luck. You get what you assay for.

The solution here is simple. Schools must admit classes as they choose, without mind to how each score will affect some artificial collegiate ranking. Doing so keeps scores in proper context and human judgment in charge.

College classes shouldn’t reflect social class. In college admissions, let’s not exalt criteria that can be gamed by kids at the top.

Michael Seringhaus is a sixth-year graduate student in molecular biophysics and biochemistry. His column regularly appears on alternate Thursdays.