YOU probably know people who follow a more or less vegetarian diet and are fit and healthy, not lacking in any nutrients and do not feel they are missing out. You may even be one.

Most educated people know that eating meat is bad for the planet, potentially harmful to their health and cruel to animals. But the meat eaters I know can rarely come up with a better reason for consuming it than: “I just really love to eat meat.”

In Meathooked, Marta Zaraska takes on the task of unpicking why so many people – in the West, especially – seem to be addicted to meat. She finds that there is no easy answer: our taste for flesh is rooted in evolutionary history, dietary requirements, chemistry and taste, big business and the political power it wields, psychology and culture.

Our ancestors’ transition from herbivory to omnivory was, initially, a positive move. As Zaraska explains: “It enabled us to grow bigger brains, encouraged sharing and politics, and helped us move out of Africa and into colder climates.”

Her journey takes us around the world, from the lush green fields of a Welsh beef farm to a steakhouse in India via the Smithsonian Institution and a research slaughterhouse at Pennsylvania State University. Along the way, she meets colourful characters who help answer her meaty question. Perhaps the most exciting is the cultural expert she meets during a bloody ceremony of chicken sacrifice at a temple in Benin: “Paul Akakpo, my guide to West African voodoo, adjusts the large python that is wrapped, jewelry-like, around his neck.”

Zaraska’s tone is light and she does well putting facts and figures to ideas we are familiar with – such as how powerful the meat industry is. “In 2011, in the US alone, the annual sales of meat were worth $186 billion,” she writes. And she has a truly alarming figure up her sleeve: “During the 2013 election cycle, the animal products industry contributed $17.5 million to federal candidates.”

So how much protein do we need each day? The daily dietary allowance recommended by the US Centers for Disease Control and Prevention is 0.8 grams per kilogram of body weight. And how far back does the habit go? Zaraska cites the oldest undisputed cut marks, which show humans started to butcher savannah animals as far back as 2.6 to 2.8 million years ago.

“Our ancestors’ move from herbivory to omnivory was, initially, positive – for growing bigger brains“

Normally a pescatarian, Zaraska describes sampling meat, fake meat and insect dishes in the course of research for this book. She enjoys the “enticing” Philly cheesesteak sandwich, but not so much the cricket she tries in an upmarket Parisian bar. “Once on my tongue, the thing collapses into greasy ash,” she writes. “I chew and chew, the wings scratching the insides of my cheeks. I certainly wouldn’t like to repeat the experience.”

Even so, Meathooked is sometimes a little judgemental of meat eaters. It makes the case for vegetarianism, though Zaraska avoids straight-out preaching until the very end. Learning the facts is an important step to giving up meat, she says, “we should
 become aware of meat’s many meanings – only then can the hooks be released one by one”.

But non-vegetarians can take heart: her vision of the short-term future is not entirely meat-free. After a whole book exploring our “addiction”, she concludes that going cold turkey (pun intended) could backfire. “Even though I do believe that in the future humanity will eat mostly plant-based foods, I also believe that pushing for dietary purity is not the way to go,” she writes.

Even after reading the book and confirming the sordid details about my destructive habit, I’m still not ready to go vegetarian – I just really love to eat meat.

This article appeared in print under the headline “Nothing quite like it?”

“Collecting butterflies may horrify conservationists, but it had negligible impact on numbers”

This article appeared in print under the headline “How to save the wild”

Man behaving badly (Image: Josef Koudelka/Magnum Photos)

WHETHER it’s skiving, sex, speeding or drinking alcohol, everything fun seems to have a warning attached. So why does behaving badly feel so good?

Richard Stephens, a senior lecturer in psychology at Keele University, UK, may not sound like the obvious person to tackle the science of deviance until you discover that he has won an Ig Nobel prize for his work on swearing. And since swearing is a particular vice of mine, I was keen to read about any advantages fruity language might confer.

InBlack Sheep, Stephens ranges far and wide, surveying the psychological and physiological research into our character flaws. He writes with the glee of someone at a theme park, which is fitting since he tells us that a ride on a roller coaster is beneficial for asthma.

He also includes chapters on those other roller-coaster rides: love and sex. Who knew, he says, what fun scientists had been having: “We’ve seen how sexual arousal lights up the brain’s reward pathways in the same way as drugs and watching your football team score
 a demonstration, if one was needed, that sex is officially fun.”

You feel that Stephens has pored over each research paper in its entirety. He is not afraid to pick apart poor methodology, praise ingenuity or point out fun details. Describing one study linking alcohol and creativity, he writes: “while having their eight shots of vodka, the volunteers watched a DVD of one of my favourite Disney movies – Ratatouille“.

And the benefits of cursing? Stephens suggests that it is key to in-group social cohesion and that people who know more swear words are more fluent linguistically – great news for my fishwife tendencies. His own research suggests swearing helps us cope with physical agony.

But the painkilling effect becomes less potent for habitual swearers. Bugger.

This article appeared in print under the headline “Just do it!”

Awareness of mortality shapes individual lives and whole cultures (Image: JĂ©rĂŽme Galland / Picturetank)

DEATH is part of everyday life. There are reminders everywhere – from novels and newspapers to that mole you’ve been meaning to get checked out. It’s too grim to contemplate, so we try to forget. But researchers have long known that awareness of death and the fear it inspires affects decision-making. The question is how?

Now social psychologists Sheldon Solomon, Jeff Greenberg and Tom Pyszczynski have some answers. In The Worm at the Core, they claim death motivates us in almost everything we do – from yearnings for immortality to voting. Voting sounds odd until the authors cite an experiment in which they assessed subjects’ intentions in the run-up to the 2004 US election. When they were reminded about death (strongly associated with George Bush after 9/11 and Iraq), the subjects were more likely to vote for Bush than Senator John Kerry. Hardly surprising, then, that individual existential crises shape cultures and fuel change.

“Individual existential crises have shaped cultures and fuelled progress”

The answer from the coalface, however, is a little different. In Smoke Gets in Your Eyes, Caitlin Doughty recalls her floundering first years as an undertaker in the US. We are spared none of the gruesome details. Describing a badly decomposed corpse she handled on her second day, Doughty writes: “Padma was more like a creature from a horror film, cast in the lead role of ‘Resurrected Voodoo Witch’.”

The colours, smells, sounds and textures she describes are a far cry from the sanitised version of death with which we are familiar.

By contrast, The Worm at the Core deals in emotions. Its authors argue that our feelings of self-worth normally shield us from morbid thoughts, but that when reminders of our mortality do penetrate, we protect ourselves by fiercely guarding our world views. This may explain why terrorist attacks can provoke outpourings of patriotism and xenophobia.

Much of the science in this rather academic book is cherry-picked from 500 studies by the researchers, former students and followers. But the authors try to make it palatable by describing the key experiments through the eyes of fictionalised subjects.

That said, I’m not sure why I needed to know about “Steve”, a rock guitarist and student, who became reluctant to use a crucifix to bang a nail into the wall after being asked about death. I would rather have known what Padma would have thought.

While The Worm at the Core uses modern research to explain human culture over history, Doughty does the opposite. She argues that we understand the realities of death less than we did 150 years ago, and she has campaigned for us to take back the process of mourning from a culture that denies decomposition and an industry in which making a corpse look “natural” requires a startling amount of intervention.

With the dark wit you might expect of an undertaker and the compassion and insight you might not, Doughty traces her own preoccupation with death from childhood, through “Deth Skool”, via the macabre side of medieval history at university. With strong story telling and vivid descriptions, she displays a protective mechanism that the psychologists seem to have forgotten – humour.

Solomon, Greenberg and Pyszczynski, on the other hand, advocate coming to terms with death by contributing to a society that outlives us all. They remind us to “grasp that being mortal, while terrifying, can also make our lives sublime by infusing us with courage, compassion, and concern for future generations”.

I prefer Doughty’s assessment. “Accepting death doesn’t mean
 you won’t be devastated when someone you love dies,” she says. “It means you will be able to focus on your grief, unburdened by
 bigger existential questions
 Death isn’t happening to you. Death is happening to us all.”

Just get that mole checked out.

This article appeared in print under the headline “Memento mori”

Journeys don’t get much more extreme than those into space (Image: NASA)

Most of us don’t have the right stuff for a space mission or shot at the South Pole, but we can have fun reading about what it takes in Extreme

I LIKE to think of myself as adventurous, although if I’m honest (and from the comfort of home), I recognise that I probably have little in common with astronauts, explorers or mountaineers. I also have no desire to find out for sure.

But Extreme, by psychologists Emma Barrett and Paul Martin, reminds us that in terms of physiology and psychology, we are all made of the same stuff, albeit in different proportions.

Unlike the similarly titled 2013 book Extremes by Kevin Fong, which looked at medicine in extreme places, Barrett and Martin concentrate on how people living in extreme environments respond to the stresses that surround them.

Within the first few pages, a couple of dozen adventurers have already died quite horrible deaths involving falls from great heights, freezing, starvation and asphyxiation, in various combinations. And then we’re thrown straight into the human biological responses to the kind of situations that lead to such deaths.

Deeply researched, and told through personal anecdotes of explorers and studies of how people cope in extreme conditions, the book is amusing, intriguing, exciting and a little horrifying. At one point we’re treated to a particularly fruity account of astronaut Jim Lovell’s two-week Gemini 7 mission, orbiting Earth alongside a fellow astronaut in “a capsule no bigger than the front seats of a small car”.

Without a bathroom, the two astronauts simply had to do their business into their specialised suits. NASA’s urine management system leaked and, because they couldn’t take off their suits to wash, the pair developed skin problems. Lovell described it as “like spending two weeks in a latrine”. Clearly, though, the experience didn’t put him off space travel as he completed several more missions at NASA.

Other familiar names, such as Ernest Shackleton and Charles Lindbergh, crop up throughout the book, recalling bedtime tales of heroism. However, the overriding message is that these people are all human, so are as flawed, irritable and irritating as the rest of us.

Still think you’ll pass on climbing Everest or crossing the Arabian desert barefoot? No problem. Barrett and Martin point out that knowing how people cope with the toughest scenarios that nature and bad luck throw at them could help all of us handle more mundane situations in our lives.

And here the book strays a little into self-help, advocating meditation for everyone and inviting people to compare their picky bosses to the oversensitive and moody Robert Falcon Scott of Antarctic fame.

The authors are right, of course, that we all have daily challenges to face – ranging from loneliness and boredom to lack of sleep and annoying colleagues. But just imagine how you would cope if those hardships stretched into weeks or months without a break.

“Imagine how you’d cope if the daily challenges you face stretched into weeks or months without a break”

So get comfy, fellow armchair explorers, and enjoy discovering how this book can help you face your own personal Everests.

This article appeared in print under the headline “Armchair explorers”

New York, 1942: checking mail for anything that might aid the enemy (Image: Bettmann/Corbis)

A history of secret messages that runs from lemon juice to codes in digital photos, Prisoners, Lovers, and Spies doesn’t quite live up to its glamorous title

THE notion that “gentlemen do not read each other’s mail” troubled the FBI when it set up a postal censorship operation in the second world war.

But as science historian Kristie Macrakis explains in Prisoners, Lovers, and Spies – a history of “secret writing” – the British had no such scruples following their success catching spies in the first world war. And intercepting other people’s communications didn’t trouble the CIA or KGB in the cold war either, nor the US National Security Agency in recent times.

So what is secret writing? Cryptographers wrestle with messages contained in a sequence of letters, numbers or symbols; detecting secret writing, however, means finding the message in the first place. The most famous method is invisible ink, which is revealed by heat or a chemical reagent. An old favourite, lemon juice, was used by Nazi spies in the UK, who could be convicted on little more than the possession of lemons and used matches.

But the loss of its spies sparked an arms race: Germany refined microdot technology – shrinking photographed documents to the size of a full stop – and new chemicals that required specific reagents, while the Allies hunted for a universal developer to reveal all messages. The race continues, as terrorists hide messages in digital photos, and superagencies hoover up all the electronic communications they can.

Not unlike the subject matter, the book proceeds in fits and starts, with most cutting-edge development and excitement centred on war or other emergencies. Yet it never quite lives up to the glamour of the title.

Still, if you fancy trying out secret writing, Macrakis has some tried and tested recipes, which use easily obtained substances. But remember: for every message you send, there has to be someone – not a gentleman – who is happy to read your mail.

This article appeared in print under the headline “Revealing all”

See gallery: Killer whales.

The was set up by the Technology Academy Finland to recognise innovation. Often dubbed the “technology Nobels”, the prize has been awarded every two years since 2004. The two finalists for the 2012 prize are Linus Torvalds, the developer of Linux, and Shinya Yamanaka, who works in embryonic stem cell research. Caroline Morley

See gallery: “Superstars of technology: The Millennium prizewinners“

Anthropologist Mary Mead has been credited with saying, “A small group of thoughtful people could change the world. Indeed, it’s the only thing that ever has.” This is as true in the world of science as it is for politics and the arts. Without creative input, support and disagreements from their friends, many famous scientists might not have made their breakthroughs. Meet some like-minded groups to whom we are all indebted. Caroline Morley

See gallery: “Four smart scientific social circles“

Read more: “Genius networks: Link to a more creative social circle“

For over 10 years photographer has been making images of all aspects of the oil industry: extraction and refining, the city of Detroit, transport and motor culture, and what happens when oil’s associated artefacts – large and small – reach the end of their useful life. The resulting collection of large-format photographs reveals how much we rely on this finite resource to fuel our modern lives. Currently on show at the newly redeveloped in London, Burtynsky’s Oil exhibition will tour other venues into 2013. Caroline Morley

See gallery: “Art in oils: Photos show grandeur of our petroleum age“

Read more: “Rubber soul: California’s 6-million-tyre mountain“