Why don't colleges and departments teach social skills? After all, to do research with a professor, a student has to have good social skills. So why not have classes that teach social etiquette and social skills? It seems that many courses in college are "book courses." Yet, when students graduate, what really matters is how they present themselves and their social skills.
During one's university life as an undergraduate, there are many opportunities to improve one's social skills and confidence as an adult. These range from the various sporting and political clubs students can join, through volunteer activities students can participate in, through coaching activities (of more junior students or even high school), all the way to activities like having a few drinks in the uni bar (soda, for US students). During the summer, one can participate in spring break-style activities or get an internship at a law firm. 

All of these activities, I dare say, help shape a student into a person. There's no assessment, no assignments, no grades, but such is the school of hard knocks.