Black Friday: Why our brains love a bargain

This is partly down toa chemical response in our brains, which urges us to buy something when we come across reduced prices.

- Cathrine Jansson-Boyd

Do you prefer Black Friday or Cyber Monday? The January sales or Amazon's Prime Day? Or perhaps you like to hold out for a good old-fashioned everything-must-go shop clearance.

For whatever your shopping habits, there's a good chance that you like the idea of bagging a bargain.

The days and weeks before Black Friday reflect this feverish appetite. You can't look anywhere online without being bombarded with adverts and offers of supposedly special deals in the run-up to Christmas.

And bricks-and-mortar retailers love putting on a sale too. Joining a long queue of fellow bargain hunters outside big shops the day after Christmas has become something of a festive tradition.

But it is not always an entirely civil event. Just recently, when premium French kitchenware brand Le Creuset held a flash sale in the English town of Andover, the police were called to manage the crowds. People had travelled from miles away and waited for hours to get their hands on some discounted swanky pots and pans.