Human societies, at all times and places, have organised themselves around the will to live with others, not alone.

But not any more. During the past half century, our species has embarked on a remarkable social experiment.

For the first time in Human history, great numbers of people – at all ages, in all places – have begun settling down as singletons.

Until the second half of the last century, most married young and parted only at death. If death came early, you remarried quickly; if late, you moved in with family, or they with you.

Now you marry later. You divorce, and stay single for years or decades.

You survive your spouses, and do everything you can to avoid moving in with others – including your children.

You cycle in and out of different living arrangements: alone, together, together, alone.

The wealth generated by economic development and the social security provided by modern welfare states have enabled the spike.

One reason that more people live alone than ever before is that they can afford to.

Yet there are a great many things that we can afford to do but choose not to, which means the economic explanation is just one piece of the puzzle.

In addition to economic prosperity, the rise stems from the cultural change  called the cult of the individual.

This cult grew out of the transition from traditional rural communities to modern industrial cities.

Not long ago, someone who was dissatisfied with their spouse and wanted a divorce had to justify that decision. Today if someone is not fulfilled by their marriage, they have to justify staying in it.

Living alone and being alone are hardly the same, yet the two are routinely conflated. There is little evidence that the rise of living alone is responsible for making us lonely.

It is the quality, not the quantity of social interactions that best predicts loneliness. What matters is not whether we live alone, but whether we feel alone. There is nothing lonelier than living with the wrong person.

There is nothing lonelier than living with the wrong person.