South Koreans who received higher levels of education are happier than those who did not attend university, a study showed Tuesday.

The report, released by the Korea Institute for Health and Social Affairs, surveyed a total of 3,655 individuals aged 19 to 75 last year.

Among those who participated, university-educated Koreans on average rated their happiness at 6.56 out of 10.

High school graduates rated their happiness at 6.17, while the average rating by those who only attended middle school was 5.58.

University-educated Koreans also had the highest life satisfaction, rating it at 6.82, followed by high school graduates, whose average rating was 6.42.

Those who never attended high school, however, had the lowest satisfaction level, 5.72, and the highest depression level of 3.63.

The research also found that Koreans tended to be happier if they were younger, religious, employed, childless and female.