How are young people presented in Romeo and Juliet?

This question leaves some room for subjectivity, as cultural attitudes on what young people should be like differ throughout space and across time. However, I will try my best to relate Shakespeare's characters in the context they were written and how we might think of them today.

Romeo and Juliet is set in a time when coming of age occurred much earlier than most consider it today. Juliet, who is just thirteen, is already considered to be of age and eligible for marriage. Bear in mind that while it was not uncommon at the time to betroth a child well before they would actually marry, Juliet is considered to be grown and so her mother is putting a lot of pressure on her to marry Paris. This expectation of Juliet to take on an adult social role speaks to a situation we can observe in other parts of the play-- many of the central characters are young people who seem to have adult roles thrust upon them before they are emotionally mature enough to handle them.

Shakespeare certainly had no problem crafting characters with distinct personalities, and this is evident in Romeo and Juliet. We encounter the dreamer Romeo, peaceful Benvolio, and fiery Tybalt, among others. What all of the young characters have in common is that they are passionate, often acting to fulfill their own emotional desires rather than based on what might be objectively helpful. As terrible as it may sound, I think that Shakespeare wanted to portray young people as capable of deep thought and feeling, but ultimately slaves to their own emotions. Of course, it is not the fault of the young people that they were expected to function in adult roles and responsibilities, but their self-serving natures proved disastrous.