This video is from BBC Ideas, short films for curious minds.

In the 1940s, German psychologist Karl Duncker created a unique experiment to test people’s problem-solving ability: he gave participants a candle in a box with some thumbtacks and he asked them to fix the candle onto the wall however they could.

This experiment was revisited by Sam Glucksberg in the 1960s – with a twist. While one group was told just to do the task to see how long the experiment took, another group was given money to complete the experiment quickly.

Does the offer of a financial reward make people do the simple task better? BBC Ideas recreated the experiment to find out.

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