Policy makers and amateur psychology pundits think "necessity is the mother of invention" - and sometimes it is, that is why that became a saying, but plain old opportunity matters a lot. Natural gas had been around for 70 years, for example, and the United States has plenty of coal, but hydraulic fracturing, a modern form of extraction, has made natural gas cheaper and led to reduced greenhouse gas emissions, a competitive advantage and a 'win' for the environment - it was developed due to opportunity, not necessity.

If you're a native of rural Mozambique who contracts a disease and becomes symptomatic, you'll likely consult a traditional healer before getting medical advice.

The need for a moral higher power may have been as necessary for adapting to a dangerous world as physical adaptations, according to a new paper.

The authors suggest that societies with less access to food and water are more likely to believe in such deities. They believe there is a strong correlation between belief in high gods who enforce a moral code and other societal characteristics. Political complexity - namely a social hierarchy beyond the local community - and the practice of animal husbandry were both strongly associated with a belief in moralizing gods, though how raising livestock factored in is a mystery, since everyone did it.

Neigh problem with injections. Shutterstock

By Adele Williams, University of Surrey

Picture this. Your prize horse needs a vaccination. Who should turn up to deliver this but a veterinary graduate of ten years, specialist in equine internal medicine and teacher to veterinary undergraduates.

Today is your lucky day! Or not.

“I specifically requested one of the male vets, but it is just a vaccination so I do hope you’ll be able to do that …”

If you lived in Hilazon Tachtit, near  the Hilazon river of Israel 12,000 years ago, you might have borne witness to a world first; the earliest known religious ceremony.

Baron Manfred von Richthofen, the Red Baron, with other members of his unit. Credit: Germany Army.

By Ingrid Sharp, University of Leeds

The idea of a war hero is still strong in the UK and in the other Allied countries.

War memorials are a central feature of the regular commemoration services, Churchill is regularly rolled out in biographical and fictional form, and there are soon to be a total of 888,246 ceramic poppies for 888,246 war heroes adorning the Tower of London.

The Slave Trade painted by a French abolitionist artist.

By Daina Ramey Berry, University of Texas

People think they know everything about slavery in the United States, but they don’t.

They think the majority of African slaves came to the American colonies, but they didn’t. They talk about 400 hundred years of slavery, but it wasn’t. They claim all Southerners owned slaves, but they didn’t. Some argue it was a long time ago, but it wasn’t.

Ancient Greeks used onions as a performance-enhancing drug. Roman gladiators ate ashes and vegetables. If common-sense does not tell us that there was no ancient civilization with futuristic technology building pyramids, anthropology certainly can.

Historic sources claimed referred to gladiators  as "hordearii" ("barley eaters") because they had an inferior diet, heavy in beans and grains, the hallmark of poor status. Even 2,000 years ago people made fun of vegetarians, it seems. Though the diet was accurate, it was not all special, according to a new paper.

It is often believed that masculine men and more feminine women were prized in ancient societies and that modern culture is beyond gender simplifications, but a
team of psychologists, anthropologists and biologists that surveyed 12 populations around the world, from the primitive to the highly developed, find that isn't so.

Credit: EPA

By Rob MacKenzie, University of Birmingham

To exaggerate is human, and scientists are human.

Exaggeration and the complementary art of simplification are the basic rhetorical tools of human intercourse.

So yes, scientists do exaggerate. So do politicians, perhaps even when, as the UK’s former environment secretary Owen Paterson did, they claim that climate change forecasts are “widely exaggerated”.