Most people feel lonely sometimes, but it usually only lasts between a few minutes and a few hours.For some people, though, loneliness can last for years.Psychologists are studying this complex phenomenon and have identified three different types of loneliness.The first kind of loneliness is temporary. It usually disappears quickly and does not require any special attention.The second kind, situational loneliness, is a natural result of a particular situation, for example, a divorce or moving to a new place.Although this kind of loneliness can cause physical problems, it usually does not last for more than a year.Unlike the second type, the third kind of loneliness usually lasts more than two years and has no specific cause.People who experience habitual loneliness have problems socializing and becoming close to others.Unfortunately, many of them think there is little or nothing they can do about it.Psychologists agree that one important factor in loneliness is a person's social contacts, for example, friends, family members, etc.We depend on various people for different reasons.For instance, our families give us emotional support and our friends share similar interests and activities.However, psychologists have found that the number of social contacts we have is not the only reason for loneliness.