South Koreans believe a person's blood type can determine their dating compatibility - making love very difficult for blood type-B men. South Korean magazines, TV shows and Internet chat rooms have been buzzing about blood types for years. But, these days, the subject of attention is just how difficult it is to strike up a relationship with type-B men. Associating blood types with personality traits has been going on for decades in North Asia. Most of the original interest started in Japan early in the 20th century and it has also taken off in South Korea. While many characteristics are associated with type-B people, the men are getting a reputation that includes, selfish, mercurial and absolutely useless as caring and devoted boyfriends. Type-B women, on the other hand, have bypassed the popular personality opinion. Last fall, a song from singer Kim Hyun-jung called "Type-B Men" soared to the top of the charts. The song had lyrics that said type-B men are quick to get angry and quick to make-up, but in the end, they will break your heart. Kim Nang, author of the best-selling book, "Dating a Type-B Man," lays out strategies for women of various blood types to deal with the pitfalls and pleasures of striking up relationships with type-B men. Another assault in pop culture came earlier this year with the release of the romantic comedy, "My Boyfriend is Type-B", which tells the frustrations of a type-A woman who falls in love with just such a man. In Asia, the subject of linking blood types to personality took off with the 1927 publication of a series of articles by Japanese scholar Takeji Furukawa called "The Study of Temperament Through Blood Type." The concept hit pop culture and mass media in 1971 when Japanese writer Masahiko Nomi expanded upon Furukawa's ideas and wrote "Understanding Compatibility from Blood Types." Today, such books on this idea are translated into Korean and filling bookshelves in Seoul. These days, South Korean women's magazines and Internet sites seem to be inundated with the subject of romance with type-B men. According to a recent nationwide survey conducted by Internet portal site www.xyinlove.co.kr, type-B men were considered to be the most difficult type to date and about 40 percent of women said they did not want to marry a type-B man. Kim Tae-suk, a doctor in the department of psychiatry at the Catholic University of Korea, said younger Koreans were buying into defining people by blood types because of what they see on TV, movies and in print. "I can definitively say there is no scientific evidence that links a person's blood type to their character," Kim said.