It is a term that is normally used in our language to refer to that individual who does not find interpersonal treatment with other people pleasant at all and so he shies away from everything that implies this question, for example conversation and treatment usually.
That is, the sullen is an individual who is on the opposite side of the person who is sociable, who is characterized especially by presenting a pronounced inclination towards relating to others and their environment. The sociable person is pleasant, affectionate and will always be predisposed to talk and help others.
In this way, the sullen individual tends to avoid contact with others, avoiding taking part in social events and preferring instead to spend time in their closest environment, where they feel most comfortable.
It can also be said that the sullen is therefore a person who has a certain fear of relating to other people, which implies that to some extent we have all gone through some stage in our lives where the term could be applied to us.
Especially in adolescence or youth it is very likely that they go through social situations that are unpleasant and from which they run away showing a rejection of them. Over time, this attitude may or may not be overcome, and it is even possible that the same person can be sullen in his public aspect and yet have no problems relating to his circle of friends.
