n legal definitions for interpersonal status, a single person is someone who is not in a relationship or is "unmarried".[citation needed] If a marriage is annulled, however, or it is found to have been void ab initio (i.e. not valid in law to start with), and assuming the person was not married previously, that individual is single, rather than unmarried. In that situation, the law behaves as though the parties thought they were married when, in actuality, they were not. The term single in its common usage is often referred to someone who isn't involved in any type of romantic relationship, whether it would be dating, engagement, or marriage.
Both single and unmarried people may participate in dating rituals and other activities to find a long-term partner or spouse. However, in some cases single people are not interested in marriage, domestic partnership, or other types of formal, committed relationships. People may remain single for a variety of reasons, including: financial and emotional or physical health issues, stress in the family, time constraints, education, career, personal preferences, advanced age, social fears or love-shyness, and even living in a society or locality where there aren't enough people of the sex one is attracted to.[1][2] Certain careers and positions require that people remain single. Sometimes, this is coupled with celibacy or chastity, either for secular or for religious reasons, such as priests, nuns and monks in certain faiths.
Loneliness can occur for some people who look for but cannot find anyone they might wish to date, especially for those suffering the loss of companionship following divorce orbereavement. Some single people, however, regard and appreciate solitude as an opportunity.
Certain situations assume that a person is married; this includes laws that vary depending on the country. For example, in the United States, Social Security relies on spouses, children, and other family, until the point that a given individual is legally elderly (65 years of age or over), or if the person has a significant disability (of any age; see Social Security Disability). It is generally assumed an individual's family member(s) will inherit or replace the holder when they are deceased. Therefore, except for the elderly and the legally disabled, US Social Security is not a benefit single people can claim.