This is a commonly used idiom: he has a chip on his shoulder.
Some people use it to indicate that he is behaving arrogantly, normally due to his success or position. Perhaps they are making a connection between the chip on his shoulder and a microprocessor chip or a blue chip stock. Actually, this is not the meaning of the idiom.
It is not related to being arrogant.
When someone has a chip on his shoulder, he is angry or feels disrespected. And he feels angry/disrespected because he is under the impression that he has been treated unfairly in the past.
And that is what it means to have a chip on one’s shoulder.
A venture capitalist once said that he looks for an entrepreneur who has a chip on her shoulder, as this means that she will try even harder to succeed. Does that make sense?
How many idioms related to war can you think of? Learn about four of them here.
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