College-admissions trickery reflects the shallow transactional mentality surrounding us. It degrades universities’ prestige and the purpose of higher education. Parents too eagerly presume big payoffs in smarts, earnings and social status. Colleges do not disabuse parents of these exaggerated notions. The scams run both ways.

College doesn’t enhance basic mental abilities. It may increase superficial smarts by expanding vocabulary but doesn’t alter inherited intelligence. Graduates are more mature but only because they’re four (or five or six) years older. Young people who complete military service are as capable and mature as college graduates of the same high-school class rank.

Some parents suppose that universities turn lackluster high-schoolers into high-performing collegiates. Maybe in rare cases. Mediocre high-school graduates who are academically mismatched to a competitive elite institution will have to struggle or even drop out. If they don’t, that college is not so elite; it has selectively lowered its standards.

Classroom instruction is not necessarily better at top universities, where only research and publishing count for promotion, not teaching undergraduates. Elite institutions draw a better peer group but one that also competes fiercely. Can your child handle that? How about large lecture classes?

Do irregular admits (including legacies and athletes) cluster in undemanding majors and avoid tough courses? Any discipline can be rigorous — if it goes deeply into the field’s philosophy, methods and empirical reasoning, but some do not. I was proud that coaches warned their athletes to not take a Roskin course — too hard. Paradoxical payoff: With weak students having removed themselves, I got mostly better and more-motivated students, thus boosting my evaluations.

Mismatched students graduating at about the same rate as their classmates indicates inflated grades, a common practice. The old “gentlemen’s C” is now a B. At many colleges, B+ or A- is the average grade. Few flunk out. Deans sometimes urge instructors to change a D or F to a C, especially if daddy is paying full tuition. Hey, we need that income.

Most measures of college admissions favor the advantaged. The validity of SAT and ACT has long been doubted because kids can prep for them. Current cases demonstrate how fraud has contaminated SAT results. Who can trust them? High-school activities are absurdly padded. Writers are hired for application essays.

High-school class rank generally predicts college success, but some secondary schools demand little in order to boost graduation rates. Prep schools have grown in recent decades to get scions of the better-off into college. Level of math is a strong predictor: If you’ve taken calculus in high school, you’ll handle college. Math level actually captures family, peer and school intellectual levels and expectations, so it tracks those with the right parents and neighborhoods. Poor and rural high schools offer less math. The best predictor is parents’ socioeconomic status, often reflected in ZIP codes.

How do irregular admits perform after graduation? Do they achieve much or just hold down jobs that do not really need a college degree? Contrary to what many believe, elite colleges do not boost chances for success. Smarts and energy do, with or without a bachelor’s. Best of all: Get admitted to Harvard but drop out your first year (Bill Gates and Mark Zuckerberg).

Conversely, uncompetitive students who graduate may run businesses poorly and federal policy even worse. Trump’s grades are as closely held as his tax returns. He reportedly shunned books and classes and just reviewed his frat brothers’ notes before exams. Kushner’s father pledged $2.5 million to Harvard as Jared applied. He has accomplished nothing on Israel-Palestine peace, Saudi Arabia or much else. Meritocracy or mediocracy?

Is college for most youngsters feasible or suitable? For the top quintile (20 percent) of high-school graduates, yes; most benefit from college and later contribute to society and the economy. For the second quintile, the chief recruits of non-elite colleges, maybe yes, depending on their motivation. The third quintile, the middle of high-school classes, and below might benefit more from work or military service, which jump-starts some underachievers.

Colleges claim they gain nothing from admission bribes, but they do. A bribing daddy pays full freight while an impecunious bright student needs tuition discounts and financial aid. The difference in revenue can top $100,000 over four years. Colleges therefore love full-tuition payers. Well-off parents of non-stellar students might visit some decent but non-elite private colleges and mention they’ll pay list price. They will get multiple acceptances. And the kid will get a better academic fit, too.

The Point: In college admissions, who scams whom? Bored, indifferent students — many aren’t sure why they’re in college — shortchange themselves and degrade their institution’s standards and standing. We need solid, demanding K-12 that gives young people the basics and prepares them for lifelong learning. After that, make college optional. Recall the skills of prewar high-school graduates.