What does it mean to behave like a lemming?

To "behave like a lemming" is a common idiom that refers to blindly following the crowd without thinking for oneself.

Here's why this idiom came about:

* Lemmings and mass suicide: A popular misconception is that lemmings engage in mass suicide by jumping off cliffs. This idea is largely false, stemming from a 1958 Disney film that staged such an event.

* Collective behavior: While lemmings don't actually commit suicide en masse, they do exhibit strong herd instincts. They often travel in large groups and follow the leader blindly.

* Blindly following the herd: This behavior has been used metaphorically to describe people who blindly follow trends, social pressures, or authority figures without questioning their own decisions.

Therefore, to say someone "behaves like a lemming" is to suggest they are uncritical, easily influenced, and lack independent judgment. It implies that they are making decisions based on what others are doing, rather than on their own thought processes.