https://www.psychologytoday.com/us/blog/living-single/201804/5-kinds-people-who-withdraw-social-life
Here are the psychological profiles of people who are shy, avoidant, and unsocial:

Shy people:

• Are anxious about anxiety. They are afraid of being afraid.
• Are more likely to engage in physical aggression than people who are not shy.
• Are more likely to engage in relationship aggression than people who are not shy.
• Do not get as much pleasure out of ordinarily pleasurable experiences.
• Are less creative than people who are not shy.
• Try to avoid unpleasant things (that’s the “behavioral inhibition system”)
• Are not very motivated to go for what they want (they get low scores on the “behavioral activation system”)

Avoidant people:

• Are more likely to engage in physical aggression than people who are not avoidant.
• Are more likely to engage in relationship aggression than people who are not avoidant.
• Do not get as much pleasure out of ordinary pleasurable experiences.
• Are less creative than people who are not avoidant.
• Are not very motivated to go for what they want (they get low scores on the “behavioral activation system”)

Unsocial people:

• Are less likely to engage in physical aggression than people who are not unsocial.
• Are less likely to engage in relationship aggression than people who are not unsocial.
• Are more creative.
• Are not very motivated to go for what they want (they get low scores on the “behavioral activation system”)