People with a greater sense of purpose live longer, sleep better and have better sex. Purpose cuts the risk of stroke and depression. It helps people recover from addiction or manage their glucose levels if they are diabetic.

In an analysis of 7000 middle aged people in the US, even small increases in sense of purpose were associated with big drops in the chances of dying during a period of 14 years. A study of more than 9000 English people over 50 years old found that even after adjusting for things like education, depression, smoking and exercise, those with the highest sense of purpose had a 30 per cent lower risk of death over nearly a decade compared than those in the lowest motivated group. Other studies show higher purpose cuts risk of heart disease by 27 per cent, stroke by 22 per cent and Alzheimer’s disease by half.