Asked to rank their life satisfaction on a scale from 0 to 10, American 15-year-olds gave an average mark of 7.4. (Wavebreak Media)

American high school students are generally satisfied with their lives. But many of their peers in other countries are happier.

Asked to rank their life satisfaction on a scale from 0 to 10, American 15-year-olds gave an average mark of 7.4, according to a study released Wednesday by the Organization for Economic Cooperation and Development, an international research group.

American students scored close to the average of 7.3 among OECD’s 35 member countries. But students in such countries as Iceland and Finland are doing much better. And an average Mexican high schooler rated life satisfaction at 8.2 out of 10.

American students also reported higher levels of anxiety over tests, bullying or a feeling of not belonging at schools, compared with many of their peers.

Teacher and parental support, spending time with friends and being physically active make it more likely that a student will be satisfied with life, according to the study. But feeling anxiety over grades and spending too much time online are signs a student may feel dissatisfied.

“In happy schools, teacher support — as perceived by students — tends to be much greater,” said study co-author Andreas Schleicher.

Studying hard does not necessarily mean being miserable. The authors highlight the cases of Finland, Switzerland and the Netherlands, where good grades and high spirits exist side by side.

There are also some gender differences. Feeling very satisfied with one’s life is more widespread among boys, while feeling low life satisfaction is more common among girls across most countries and cultures. Why that was the case was unclear from the report.

The study was conducted in 2015 with 540,000 randomly selected kids who completed written tests and questionnaires.

Tom Loveless, who researches education policies with the Brookings Institution in Washington, was skeptical about the way the survey looked at U.S. high school students. He said that at the time of the study, most 15-year-old sophomores would have spent a little more than a year in their current high school, so their well-being could have been shaped by other factors.

— Associated Press