In my language, there is a saying whose literal meaning in English is:

A melon gives colour to another melon”.

This cliché/saying is used at places where one person is excited/instigated/musters courage/or behaves the way he has never behaved just because his colleague/friend is behaving that way.

For example, one boys in a class starts to wear his trousers very low, and others start to follow. One student goes for “spiky hair”, others too. I would like to know if there is any saying in English for such situations.


I think there is such a saying in English, but I can't come up with it at the moment.
I can only think of pejorative expressions for someone who has no mind of his own, like, "He goes whichever way the wind blows," or, "He just follows the crowd."

There's also "tarred by the same brush," referring to guilt by association, only slightly related.

I'll keep thinkin'. Emotion: thinking
Nothing comes to mind that has the exact same nuance, but these are related expressions, perhaps.

Monkey see, monkey do.

Birds of a feather flock together.

jump on the bandwagon

take a leaf out of someone else's book
follow in someone else's footsteps
get in with the wrong crowd

follow the crowd

follow the herd

egg on

herd mentality