“豹子改变不了身上的斑点”是个比喻，指江山易改本性难移。

"The leopard cannot change his spots" is just a figure of speech.

《柯林斯英汉双解大词典》

她知道我本性难改。

She knows I'll never change.

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另一个促使人们倾向于否定本性难移假设的因素是，这一概念经常被滥用，被当作大多数不人道行为的挡箭牌。

Another factor contributing to the tendency to deny the assumption of a fixed human nature was that the concept has so often been abused as a shield behind which the most inhuman acts are committed.

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