‘Don’t judge a book by its cover.”

When parents offer this advice to kids, they rarely mean it literally. But a couple of years ago I found myself saying it in a bookstore — about actual books and covers. My daughter, a voracious reader, was turning down my suggestions for books because the characters on the front were not girls. Or not the right age. Or didn’t seem to be in a setting that she could relate to.

Sadly, this isn’t just a popular attitude among 9-year-olds; it’s apparently shared by those who run our universities.

That is, the educators and administrators seeking to shape the next generation (and the generations after that) don’t understand the basic purpose of education: To expand students’ minds, to challenge their assumptions, to guide them out of their comfort zones.

This was made plain in a new report from the National Association of Scholars, which looks at the reading that colleges assign to freshmen over the summer. Most are recent works — more than half were published after 2009.

About three-quarters of the assigned readings are nonfiction; the overwhelming majority are memoirs or biographies.

And almost none are foreign works in translation.

In other words, even if kids are going to encounter a character who comes from a different background, the book will most likely be written in familiar style and language and most of the experiences will be, well, relatable.

Yet more than half of the schools also have the author come to speak on campus — which tells you a lot about how schools view this kind of reading.

These texts are completely accessible, yet administrators still think students need to hear the story from the horse’s mouth in order to relate. Nothing is left to the imagination.

The freshman reading program is so lucrative that many publishers devote an entire department to selling schools on particular works. Penguin, for one, recommends questions to guide schools in deciding which work to assign.

And right after asking if it tells a good story, the second criterion is: “Does it feature a protagonist students can relate to? They might be the same age or be dealing with similar life situations (change, challenge, adversity).”

That’s how you get “The Other Wes Moore” and “Enrique’s Journey” and “I am Malala” as among the most commonly assigned summer reading, while the classics are notably absent.

Notes the NAS report: “With few exceptions, the hundreds of common reading programs across the country ignored books of lasting merit. Austen, Balzac, Cather, Dostoevsky, Eliot, and Fitzgerald were not to be found.”

Even modern classics get ignored. The study’s authors search in vain for mentions of Martin Amis, J. M. Coetzee, Don DeLillo, Annie Dillard, Mark Helprin, Alice Munro, V. S. Naipaul, Marilynne Robinson, Philip Roth, Richard Russo, Mario Vargas Llosa and Tom Wolfe. ?

The study concludes, “The common reading genre is parochial, contemporary, commercial, optimistic, juvenile, obsessed with suffering, and progressive.”

Over time, through my own efforts and her teacher’s assignments, my daughter figured out there were plenty of stories that appealed to her even though the characters were older or from other parts of the world or boys.

But some children will never have the benefit of these efforts: 11-year-old Marley Davis, a Philadelphia native, made a media splash by launching a drive to collect 1,000 books about black girls because she was “sick of reading about white boys and dogs.”

It’s perfectly understandable that Marley would want to read books about people who look like her — one expert on WNYC explained that this was important to boosting kids’ “self-confidence.”

But, contrary to the views of our experts, that’s not why we read. Good books are supposed to have the power to transcend the race, sex and class of their characters as well as the time and place of their settings.

And whatever we think of a 9-year-old’s reading tastes, it certainly isn’t the point of a college education — a fact lost on those who run our colleges.

Naomi Schaefer Riley is a senior fellow at the Independent Women’s Forum.