The phrase “soft bigotry of low expectations” is inevitably associated with George W. Bush, who used it frequently. But whatever your politics, the idea has undeniable merit: If schools don’t expect much from their students, the students are not likely to accomplish much.

A new international study, set to be released Tuesday, argues that the United States has an expectation problem.

More so than any of the other 29 countries in the study, principals in American schools believe that many of their students come from socioeconomically disadvantaged homes. Based on the views of principals, a larger share of children in the United States are “socioeconomically disadvantaged” compared with those in Brazil, Malaysia, Mexico, Romania and various other countries.

The author of the paper is Andreas Schleicher, the director of education and skills research at the Organization for Economic Cooperation and Development. Mr. Schleicher oversees the widely cited PISA test, which is the basis for comparing student performance around the world.