As the daughter of an weatlhy and influential family scion, Juliet's prescribed role in life would have been to have entered into a marriage that would have brought additional riches and influence to her family. This is, of course, what Capulet has in mind when he arranges her marriage to Paris, a kinsman of the prince. When Juliet begs not to be forced to marry Paris, her father explodes in a tirade that demonstrates just how important marriage was to these noble familes:
God's bread! It makes me mad....
Alone, in company, still my care hath been
To have her match'd; and having now provided
A gentleman of princely parentage...
And then to have a wretched puling fool,
A whining mammet, in her fortune's tender,
To answer ‘I'll not wed, I cannot love;
I am too young, I pray you pardon me’!
But, an you will not wed, I'll pardon you.
Graze where you will, you shall not house with me.
...hang, beg, starve, die in the streets,
For, by my soul, I'll ne'er acknowledge thee,
Nor what is mine shall never do thee good.
In other words, Capulet is prepared to disown his daughter if she does not fulfill her expected role. Her familial obligations are, in a sense, why she has to keep her love for, and her eventual marriage to, Romeo. This is, of course, her downfall, and part of the ultimate tragedy of the play. Yet it has to be noted that even Romeo, whose options in society were nowhere near as limited as Juliet's, faces similar constraints. So not only society, but the destructive feud between the Capulets creates a poisonous atmosphere that consumes the two lovers.