it's (only/just) human naturespokenNATURAL used to say that a particular feeling or way of behaving is normal and natural 〔某种感情或行为〕是正常的，是人之常情it’s (only/just) human nature• It's human nature to put off doing things you don't like to do.• But it's human nature that people-male or female-will do what they are allowed to get away with.
→ it’s (only/just) human nature at human nature(1)