a knee-jerk reaction — instinctive, unthinking reaction
collocationC1IELTS 7+neutralcommon
an immediate response to something, made without thinking carefully, often emotional or automatic rather than considered.
Say it like a native
Textbook His response was immediate and made without any careful thought.
Native It was a knee-jerk reaction.
The idiom names the whole thing — automatic, unconsidered, usually criticised.
Pattern: a knee-jerk reaction (to something)
In use
- His comment was just a knee-jerk reaction to the criticism, not a well-thought-out response.communication
- In my opinion, governments should avoid making knee-jerk reactions to public pressure and instead take time to consider the long-term consequences.IELTS speaking
Common mistake
✗ Don't make a knee-jerk reaction.
✓ Don't have a knee-jerk reaction. / Don't react in a knee-jerk way.
You 'have' a knee-jerk reaction (or react that way); 'make' sounds off.
Common collocations
a knee-jerk reaction/response— reaction, response, avoid, typical
Don't confuse it
Unlike a simple 'quick reaction', a 'knee-jerk reaction' emphasises that the response is automatic and not carefully considered, often implying it is not the best or most reasonable response.