How This Text Is Built

Can You Do Two Things at Once?

People say they multitask. Mostly they do not. The brain can run two tasks together only if at least one is automatic. Walking and talking works because walking is automatic for an adult. Reading and listening to speech does not, because both need the same language system. What feels like multitasking is usually rapid switching. Each switch costs time — a fraction of a second to disengage and re-engage — and the costs add up. In experiments, people doing two tasks alternately take substantially longer in total than doing them one after the other, and make more errors. They also do not notice. Switching feels efficient because you are busy the whole time. The practical conclusion is unpopular but consistent: for anything demanding, doing one thing at a time is faster.

Two Plants, Two Histories

Tea and coffee are both leaves or seeds steeped in hot water, and both became national habits. How they got there could hardly be more different. Tea came to Britain through a monopoly. The East India Company controlled the trade for nearly two centuries, and the government taxed it so heavily that by the 1770s most tea drunk in Britain had been smuggled. When the tax was cut in 1784, smuggling collapsed almost overnight. Coffee spread through places rather than trade. The coffee house arrived in Britain in the 1650s and became somewhere to read newspapers and argue. Lloyd's of London and the London Stock Exchange both began in one. Tea won the home; coffee won the meeting. Neither plant grows in Britain. Both habits are entirely imported, and both are now so ordinary that they are thought of as native.