The happiness index for Korean teenagers was the lowest among the 23 OECD member states for the third consecutive year, according to a survey released on Wednesday by two civilian institutes.

The “subjective well-being index” for Korean students between the ages of 10 and 18 was 65.98, far lower than the OECD average of 100, the survey showed. The index for Spanish teenagers was the highest with 113.6 points.

The Bang Jeong-hwan Foundation and the Institute for Social Development Studies at Yonsei University jointly conducted the survey -- titled the “2011 well-being index for Korean children and adolescents, and its international comparison” -- on 6,410 teenagers between March and April.

Experts said that the pressure on Korean teenagers to score high marks at school and the cutthroat competition to enter top-notch universities appears to be the primary reasons why they feel unhappy.

“Teenagers are in the process of establishing their own identities. But they are too busy with studies at school and hagwon (private educational institutes),” Youm Yoo-sik, sociology professor at Yonsei University, who led the survey, told The Korea Herald.

“There appears to be no connection between their lives at school, home and hagwon. There should be a measure to connect them so that they can feel more secure.”

By Song Sang-ho (sshluck@heraldcorp.com)