Being short on money can cost you the IQ-equivalent of a sleepless night

Studying the same Indian sugarcane farmers before and after harvest, researchers found their cognitive test scores dropped when money was tight and recovered once it wasn't — a swing comparable to losing a full night's sleep. Scarcity itself seems to tax mental bandwidth, leaving less of it for everything else.

— Sendhil Mullainathan & Eldar Shafir, Scarcity: Why Having Too Little Means So Much — 2013; underlying study in Science, 2013
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