Who are the loneliest among these people according to the speaker?

Many people feel lonely sometimes, but it usually only lasts between a few minutes and a few hours．This kind of loneliness is not serious．In fact, it’s quite normal． However, for some people, loneliness can last for years．
    Psychologists are studying this complex phenomenon in an attempt to better understand long-term loneliness．Most researchers agree that the loneliest people are between the ages of 18 and 25．So a group of psychologists decided to study a group of college freshmen．They found that more than 50% of the freshmen were lonely at the beginning of the semester as a result of their new circumstances．But they had adjusted after a few months．13% were still lonely after 7 months due to shyness and fear．They feel very uncomfortable meeting new people even though they understood that their fear was not reasonable．They remained unhappy because they were afraid to make new friends．And they thought that there was little or nothing they could do to improve their condition．