Final answer:
Elizabeth thinks Wickham marries Lydia due to Lydia's lack of judgment and her flippant nature, while Lydia's reasons for marrying young stem from a desire for excitement and social advancement, reflecting societal influences of the time.
Step-by-step explanation:
Elizabeth Bennet believes Wickham marries Lydia primarily due to Lydia's lack of better judgment and her frivolous nature, which made her an easy prey for Wickham's unscrupulous ways. Lydia marries so young because of her impetuous and thoughtless disposition, prioritizing immediate gratification and romantic excitement over prudent judgment.
In the context of Pride and Prejudice by Jane Austen, the driving forces behind Lydia's early marriage are her desire for adventure and to enhance her social status by being married, instead of understanding the full commitment that marriage involves.
Social and historical context also explains why young women often married early; typically, between the ages of fourteen and eighteen. They were seen as more sexually pure and easier to control. High-ranking women brought dowries into their marriages, which provided them with some leverage and protection from their families, while lower-class women depended on their husbands to improve their status.
Ultimately, Lydia's actions reflect these societal influences, with her rash decision to elope with Wickham indicating a desire for independence and a misunderstanding of the gravity of marriage.