Image Credit... Tamara Shopsin

In short, these are people who not only swallow many of the maxims for success but take them as absolutes. At some level they know that it’s possible to succeed after falling short (build on your mistakes: another boilerplate rule). The trouble is that falling short still reeks of mediocrity; for them, to say otherwise is to spin the result.

Never accept second best. Always be true to yourself.

The burden of perfectionist expectations is all too familiar to anyone who has struggled to kick a bad habit. Break down just once — have one smoke, one single drink — and at best it’s a “slip.” At worst it’s a relapse, and more often it’s a fall off the wagon: failure. And if you’ve already fallen, well, may as well pour yourself two or three more.

This is why experts have long debated the wisdom of insisting on abstinence as necessary in treating substance abuse. Most rehab clinics are based on this principle: Either you’re clean or you’re not; there’s no safe level of use. This approach has unquestionably worked for millions of addicts, but if the studies of perfectionists are any guide it has undermined the efforts of many others.

Ms. Provost said those in her program at U.C. Davis often displayed symptoms of obsessive-compulsive disorder — another risk for perfectionists. They couldn’t bear a messy desk. They found it nearly impossible to leave a job half-done, to do the next day. Some put in ludicrously long hours redoing tasks, chasing an ideal only they could see.

Image Credit... Tamara Shopsin

As an experiment, Ms. Provost had members of the group slack off on purpose, against their every instinct. “This was mostly in the context of work,” she said, “and they seem like small things, because what some of them considered failure was what most people would consider no big deal.”