"Origins of words" by Susie Dent, Countdown 18/08/17 (having chip on one's shoulder)

I'm going to talk about "having a chip on one's shoulder", which mean that you're walking obviously with some kind of prejudice or you're overly sensitive about some particelar subject. So where does the chip come from? Obviously it's figurative these days, but it was to be very, very literal. So, for example, if you take one record in the Oxford English Dictionary from 1830, this is from the Long Island Teleghaph - "When two churlish were determined to fight, a chip would be placed on the shoulder of one and the other demanded to knock it off at his peril". So the idea was thet if somebody fancied a spar, they wood put a woodchip, a simple woodchip, on their shoulder and if there was a rival aroundthat fancied a fight, they would simply knok it off the shoulder and that would be agreeing to have a bout of fighting. So obviously that spoiling for the real fight gave way to the idea now of someboby who's just a little bit belligerent and quick to take offence, and usually have some specific feeling of inferiority, so it moved very much from the concrete to the literal. But other way of the signalling that you are ready for a fight,  they was also crept into English as idioms, really, so throwing your hat into the ring, for example, simply means that "I'll have a go". But the ring in question was a boxing ring, it was simply a circle of onlookers and the fighters would gather in that ring, inside this circle, hence the idea of a boxing ring. So any Jack-the-lad who fancied his chances, really, in a about would throw in his hat. I'm not quite sure why, but probably more reliable way of signalling that you were ready to action rather then just shouting above the tumult of the crowd. So two kind of fighting idioms, if you like, that have crept into figurative English, but had their heart in boxing.