The work of a male ...

Men are designed to make nests. Women are designed to cuddle-up in them. Some men do not make nests. Some women do not lie in them. Modern industrial life provides the technology to free men and women from their evolutionarily constrained roles and made nest-making an intellectual task for some and a practical task for others.

Still, our lives still go in cycles of nest-making and nesting and all of the traumas and joys that go with it. We are technologically far more sophisticated than birds in some respects but we pretty much behave like them, the men – and increasingly the women -- spending the working hours earning enough money to pay for the nest and all of the material stuff we put in them.

Environmental events trigger very specific nest-supporting events. The onset of winter drive us inside, preferably into a cacoon of warmth. In earlier times we retreated into caves kept warm by wood-kindled fires. That is why there is no greater sense of dream-like comfort than kindling the campfire, with the dog our early warning signal friend lying in proximity, on the watch.

When winter is over we spring-clean. In pre-modern days we swept our caves and buried the waste which today is the treasure for the palaeontologists – the bone hunters – and the archaeologists – the ancestral garbage hunters. In modern times, the house or dwelling is spring-cleaned and the heaters put away.

The seemingly endless repetition of the nesting cycle, when you add it all up, amounts to the human contribution to global warming and climate change. The cycle we face, climatologists tell us, is colder winters and warmer summers. If we continue as we are, we will use more energy to keep us warm in winter and cool in summer.

In modern times the nesting drive has led us to consume energy on a scale proportionate to our growth in population. Fossil and carbon based fuels have replaced fires to keep us warm, though most human beings only have the resources for the traditional fire. In summer we use the energy to keep some of us cool, those having the resources, to have air-conditioning.

Although the technology and social norms have changed especially over the last hundred or so years, our behaviours are little different to when we first walked the earth as modern homo sapiens about 150,000 years ago: for women, home comfort is more important than anything else. For men, it is to go on the hunt for the resources to make home comfort possible.

The male sense of accomplishment and well-being, their evolutionary psychology, depend on how well they see themselves building the nest. They are hungry for their partners and wives’ approval in how much of a nest of quality they can provide and how much the stuff they put in it give the level of comfort the other half has come to expect.

The women on the other hand derive their greatest emotional contentment by how well the nest supports the raising and nurturing of the young, the children who in human society require 18 or so years of protection, nurturing and training. It is a role finessed over thousands of years and it works: sex-role differentiation is the secret to our survival.

A number of technological innovations have freed especially women from the social aspects of our evolutionarily conditioned behaviours. Birth control technology is one that gave women control over their fertility. Equality of opportunity gave them access to education. Child-care institutions outsourced nurturing of the young.

And so, women too generate the material resources needed for nesting, but it comes at a cost: the children see less of them. The men do not necessarily make up the time with them. More women chasing income has not been accompanied by fewer men chasing less income. Clearly, women occupy many more leadership roles today.

Women bring their evolutionary psychology into leadership roles: they tend to be more inclusive, less hierarchical, more open, all qualities associated with the nurturing role. There are of course women who act just like men. Because we have the ability to learn, some women quickly acquire the habits of men.

War and disease have left many orphaned children whom today have to make their nests. The social configuration of nest-making has changed radically in modern times therefore. Still, what drives year in year out, season after season, like birds, is nest-making.