All parents want their kids to do well. But unrealistic expectations not only have potentially damaging long-term psychological effects, they can hurt kids academically in the here and now. That’s according to a new study that finds getting kids to do well is even more of a tightrope than we thought. Some pressure does help children achieve more, but expecting the unachievable only makes them do worse.

Researchers at the UK's University of Reading looked at the numbers from a study of more than 3,500 students in Germany from 2002 to 2007. The study, according to an article in Science Daily, “assessed student math achievement as well as parental aspiration (how much they want their child to earn a particular grade) and expectation (how much they believe their child can achieve a certain grade) on an annual basis.” They found that when parents pushed kids to achieve, they did rise to meet the expectations. But when parents tried to nudge kids past their realistic potential, the effort backfired, and the students actually did worse.

To double down on those findings, researchers reviewed the results of a study involving 12,000 kids and parents in the U.S. The two-year investigation came up with the same findings as the German survey, and offers a cautionary tale for parents.

"Much of the previous literature conveyed a simple, straightforward message to parents—aim high for your children and they will achieve more," says Kou Murayama, who led the study. "Unrealistically high aspiration may hinder academic performance. Simply raising aspiration cannot be an effective solution to improve success in education."

Murayama added that too much parental aspiration can be “poisonous.”

(h/t Science Daily)