Over a fifth of all sex criminals are highly educated, having graduated from college or higher, a survey shows.

Among 13,377 sex crime offenders in 2008, 2,706 or 20.2 percent had college or higher academic degrees, according to the 2009 Criminal White Paper released by the Legal Research and Training Institute yesterday.

Some 4,602 offenders or 34.4 percent were high school graduates and 1,397 or 10.5 percent were middle school graduates.

Almost six percent of the sex criminals were only primary school graduates or had no academic backgrounds, showed the paper.

In other felonies, the number of highly educated offenders was visibly low, the research also showed.

In 2008, only 13 percent of murderers, 10.9 percent of thieves and 9.3 percent of arsonists had college degrees.

The percentage of college-graduate sex criminals, in contrast, has always exceeded 20 percent since it reached 21.6 percent in 2001, according to the study.

Sexual violence is distinguished from other forms of violence, which is often motivated by psychological instability caused by poverty or distorted human relationships, according to experts.

"An ordinary man, with no tendency towards physical violence, may easily (commit) sexual violence when he lacks an ability to become intimate with women," said an official of the Korean Institute of Criminology.

The traditional Confucian taboo of sexual expressions has also caused distortion in Korean society, some said.

"Despite its seemingly liberal sex culture, Korean society still lacks sufficient communication between both genders on sexual issues," said an official of the Korea Sexual Violence Relief Center.

"Many sex criminals, despite their intellectual abilities and academic achievements, are unable to regard women's sexual freedom as their basic human right."

The present education system needs to be revised to educate students on proper communication and sexual freedom, the official added.