That young man is an introvert.

轻人是一性格内向的人。

And extroverts also tend to be more personable, faster to charm, soakers of attention. while introverts often are alone in a corner.

外向的人给人感觉更英俊，更快的让人着迷，更引人注意。同时内向的人经常独自呆在角落里。