In more selective omiai, the candidates and their families were judged on a larger set of criteria aimed at determining the suitability and the balance of the marriage. This criteria is formally known in Japan as . It included level of education, income, occupation, physical attractiveness, religion, social standing, and hobbies. The participant's also played a large role. Many were fearful of the possibility that a potential candidate's blood was contaminated with diseases such as epilepsy, neurosis, or mental illness. The fear was so prevalent that the Eugenic Protection Law of 1948 was passed to legalize sterilization and abortion for people with a history of mental defects and other hereditary diseases. Social status also played a large role in selecting a candidate. Ideally, paired candidates and their families would be of equal social status, so some candidates had a hard time finding a mate if their family was not of a certain social status. Family lineage also affected the quality of candidates historically; for example, a candidate with samurai blood was more likely to be picked than one with ancestry from a different class, especially during the Tokugawa-era.