The Secret to High Teacher Ratings? Cookies.

It may not feel great to buy love and obedience with cookies, quarters, and trinkets, but it works — whether the subject of your bribe is in elementary school or college.

Eat your hearts out, educators. A new study suggests that the promise of cookies is all it takes to convince students to give teachers high ratings on end-of-year evaluations. Researchers asked professors at the University Hospital of Muenster in Germany to randomly hand out cookies to some students before administering these surveys, and found that hands greased with cookie dough were more likely to praise the teachers, the teaching materials, and the quality of the course.

Since these surveys can influence curricula, not to mention hiring and funding decisions, one implication of the study is that it’s probably time to place less stock in how students evaluate their teachers. “This is a totally inadequate tool to measure quality if you can mess with the system that easily,” according to the study, due to be presented at the Euroanaesthesia conference in Denmark. “A higher student satisfaction does not necessarily correlate with a higher quality of education.”

But for parents, the implications extend far beyond the classroom. Because small bribes are effective on kids, too, and can encourage good behavior. One 2016 study of 8,000 children found that a mere 25-cent bribe doubled the number of kids who ate their fruits and vegetables; another study of 1,500 children found that rewarding kids who ate healthy with inexpensive pens and rubber bracelets created long-term positive eating habits even when the gravy train ran dry. Beyond questioning the value of teacher surveys, this study drives home the point that a little creative bribing can go a long way toward encouraging positive behaviors.

It may not feel great to buy love and obedience with cookies, quarters, and trinkets, but it works. Sometimes your constituents just want hand-outs.

“On the upside,” the study author quips, “our findings may stimulate new ideas for teachers who seek to improve and control their [evaluation scores] by manipulating food-related interventions.”