Tybalt claims that he hates "all Montagues." Do you think this is a valid perspective to have about a group?

No.

Explanation:

Though a certain group may tend to do similar things that lead someone to hate them, this cannot be made true for all members of this group. This is called a "blanket generalization", which may be defined as a set of expectations applied to all the members of one group, typically negative, and usually faulty as a result of bad experience. Blanket generalizations are usually over-generalized.

Members of a group aren't all the same. Even when most of them truthfully have the commonality of a certain negative trait, it is unfair to group the members of that group who are unlike the majority of the group simply because they belong in that group.

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