What is the difference between Marianna and Elinor on their reactions to similar situations?

Elinor is composed, Marianne is foolhardy. Elinor is careful, Marianne rushes into situations without thinking them through. Elinor isn't prone to being swayed by others, Marianne is easily led. These observations are evident in their handling of affairs of the heart. Elinor is the one who supports Marianne through her heartache; she is the realist, whereas her sister is the romantic.

Marianne Dashwood doesn't have much sense or sensibility. She is quick to fall in love and is a drama queen. She is in fact rather manic with her emotions. Until the end of the story, she is driven purely by emotion. Elinor Dashwood is the opposite. She is practical and able to seperate herself from matters of the heart and common sense. Unlike her sister, Elinor doesn't pine for a man to "complete" her. Marianne can't keep away from her man and gives over her lock of hair to Willoughby (kind of like a promise ring?) which Elinor finds disturbing.