If there’s a sign of the times in college admissions, it may be this: Steven Roy Goodman, an independent college counselor, tells clients to make a small mistake somewhere in their application — on purpose.

“Sometimes it’s a typo,” he says. “I don’t want my students to sound like robots. It’s pretty easy to fall into that trap of trying to do everything perfectly and there’s no spark left.”

What Mr. Goodman is going for is “authenticity” — an increasingly hot selling point in college admissions as a new year rolls around.

In an age when applicants all seem to have volunteered, played sports, and traveled abroad, colleges are wary of slick packaging. They’re drawn to high grades and test scores, of course, but also to humility and to students who really got something out of their experiences, not just those trying to impress colleges with their résumé’.

The trend seemingly should make life easier for students — by reducing the pressure to puff up their credentials. But that’s not always the case.

For some students, the challenge of presenting themselves as full, flawed people cuts against everything else they’ve been told about applying to college — to show off as much as possible.

At the other extreme, when a college signals what it’s looking for, students inevitably try to provide it. So you get some students trying to fake authenticity, to package themselves as unpackaged.

“There’s a little bit of an arms race going on,” says Mr. Goodman, who is based in Washington. “If I’m being more authentic than you are, you have to be more authentic next month to keep up with the Joneses.”

Colleges say what they want is honest, reflective students. As Jess Lord, dean of admission and financial aid at Haverford College in Pennsylvania puts it, “everybody’s imperfect.”

“Since that’s true for all [student], those that portray that aspect of themselves are that much more authentic.”

How do colleges find authenticity? They look for evidence of interests and passions across the application — in essays, interviews, recommendations, and extracurricular activities.

“What we see are the connections,” said Christopher Gruber, dean of admission and financial aid at Davidson College in North Carolina. If a student claims working in student government has been a meaningful experience, it’s a more credible claim if recommenders have picked on that as well.

“That, in my mind, gives authenticity to an application, when you’re reading things more than once,” Mr. Gruber said.

But in the age of the hyperachieving student, authenticity doesn’t always come easy. Some schools, such as MIT, now specifically ask students to write about disappointment or failure. Many can only come up with a predictable and transparent answer: perfectionism.