Humans

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MORE than 2300 years ago, Aristotle argued that happiness was the highest good. Later, the US founding fathers considered its pursuit to be an unalienable human right. These days, you will find countless books promising to reveal the secrets of a happy life. But have millennia of philosophical and scientific enquiry taught us anything about how to achieve that?
First, let’s look at how people who study happiness measure it. One of the most common strategies is to ask people to rate statements such as “In most ways, my life is close to my ideal” and “If I could live my life over, I would change almost nothing”. These aim to capture someone’s overall satisfaction with life, rather than their mood on a specific day.
That makes sense, says Richard Layard, co-director of the Community Wellbeing Programme at the London School of Economics, because asking people to sum up their general contentment is often more practical than measuring their emotional state over an extended period. The other thing, says Layard, is that general contentment fits better with philosophical definitions of happiness as an overarching quality, as opposed to transient pleasures.
Using this kind of scale, psychologists have attempted to identify the specific ingredients that contribute to happiness. Contrary to the idea that “money can’t buy happiness”, income does play a role: it is easier to feel pleased with your lot when you don’t have to worry about bills and can treat yourself to luxuries.
We are also influenced by the riches of others – we are less happy if we know our neighbour is earning more than us. … More

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IMAGINE a child, running barefoot through a forest, and a broken glass bottle buried just beneath the soil. What’s worse: that a present-day child steps on the shards, or that a child in 100 years from now does?
This question, posed by philosopher Derek Parfit in the 1980s, was intended to clarify our moral obligations towards unborn generations. Knowingly risking harm to a future person, he argued, is just as bad whether it is today or in a century.
Parfit’s ideas inspired a branch of moral philosophy called longtermism. It rests on three premises: future people matter, there could be a lot of them and we have the power to make their lives better or worse. Ensuring the future goes well should therefore be a key moral priority of our time.
All of which seems reasonable, at first glance: it apparently promotes the universal values of stewardship, the duty to posterity and being a “good ancestor”. But longtermism has proven controversial, with some critics arguing that it is a “dangerous ideology” that permits or even encourages the suffering of people alive today.
Is that fair? To make up your own mind, the first thing you need to know is that longtermism comes in different flavours. Many of the most strident criticisms focus on the implications of “strong longtermism”, a variant introduced in a 2021 paper by the University of Oxford’s Hilary Greaves and William MacAskill, which says that it should be the top moral priority of our time.
This would have striking consequences for how money is spent in the real world. Indeed, it is already having an influence. … More

Wine drinkers have a lot of options when choosing their preferred varietyKlaus Vedfelt/Getty Images
Variations in our salivary proteins may explain why different people can like different wines. Researchers have linked the concentrations of two types of proteins to how intense wine drinkers find a wine’s notes, such as fruity or floral, and their preferences for the alcoholic drink.
A person’s wine preferences may at least partially come down to their cultural background, knowledge of the drink and individual taste. But Kate Howell at the University of Melbourne, Australia, and her colleagues … More

Claire Plumridge
PICTURE the scene: you are making a cup of tea for a friend who is on their way and won’t be arriving for a little while. But – disaster – you have already poured hot water onto a teabag! The question is, if you don’t want their tea to be too cold when they come to drink it, do you add the cold milk straight away or wait until your friend arrives?
Luckily, maths has the answer. When a hot object like a cup of tea is exposed to cooler air, it will cool down by losing heat. This is the … More

A pierced deer tooth discovered in Denisova cave in SiberiaMax Planck Institute for Evolutionary Anthropology
DNA that seeped into an elk tooth pendant about 25,000 years ago has yielded clues about the ancient woman who wore it.
The tooth, worn as a necklace bead, probably absorbed DNA from the person’s sweat as it lay against her chest and neck. Marie Soressi at Leiden University in the Netherlands and her colleagues were able to extract that DNA without damaging the tooth through a new process that took eight years to develop. The technique might reveal unprecedented details about the social customs and gender roles of ancient populations, says Soressi.
“For the first time, we can link an object to individuals,” she says. “So, for example, were bone needles made and used by only women, or also men? Were those bone-tipped spears made and used only by men, or also by women? With this new technique, we can finally start talking about that and investigating the roles of individuals according to their biological sex or their genetic identity and family relationships.”Advertisement
Scientists have often suspected that ancient tools, weapons, ornamental beads and other crafted artefacts contain DNA from the people who touched them. But getting DNA out of these objects typically means removing sections for analysis – causing permanent damage. “We absolutely didn’t want to do that,” says Soressi.
To see if DNA could be coaxed out of ancient artefacts without destroying them, Soressi and her colleagues tested numerous combinations of chemicals and heating regimes on 10 previously excavated artefacts from Palaeolithic caves in France. They found that placing them in a sodium phosphate solution and raising the temperature incrementally from 21°C to 90°C (70°F to 194°F) led to the release of relatively large amounts of human DNA with no damage to the specimens.
The team then tested the procedure on another 15 excavated bone specimens from one of the caves. Genetic sequencing revealed DNA from many different humans – probably the scientists and technicians who had worked with the artefacts across the years, says Soressi.
To avoid such modern DNA contamination, the researchers then tried their technique on four tooth pendants excavated by colleagues in Russia and Bulgaria who wore sterile gloves and face masks. Their analysis revealed mostly animal DNA that matched the species used to make the pendants.
One tooth pendant from Denisova cave in Russia, however, also contained human DNA fragments, primarily from a single individual. There was enough genetic material for the researchers to positively identify a female Homo sapiens, in addition to the elk (Cervus canadensis) that provided the tooth.
While the human might have rubbed her DNA into the pendant if she had crafted it, the large quantity of DNA recovered suggests she was the individual who wore it, says Soressi. “As a porous material, that tooth was likely soaking in sweat,” she says. “It worked like a sponge, pulling in that human DNA and trapping it there for 25,000 years.”
The DNA showed that the woman was closely related to an ancient tribe that, thus far, had only been found more than 1500 kilometres to the east.

Daniella Bar-Yosef Mayer at Tel-Aviv University, Israel, finds the paper “very exciting”, in part because it could help explain the purpose of ancient jewellery. For example, it might signal something about the identity of the wearer or their group, or their marital status, she says. “If we find them in different contexts on men, on women or children of this species or another species, or different age groups, that would give us some better clues about what they’re meant for.”
The technique might also help resolve long-running scientific debates about whether certain artefacts were made and worn by Homo sapiens or Neanderthals, she adds.
The study could open the door to DNA analyses of museum artefacts across the globe, says David Frayer at the University of Kansas. “Curators are often hesitant to allow their specimens to be damaged for DNA analysis, however small the extraction,” he says. “The absolute strength of this paper is that [their] procedure gets around that. If it can be extended to specimens cleaned long ago, this would represent a great leap forward for ancient DNA work.”

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Around 1 in 10 people are left-handedEva-Katalin/Getty Images
Fewer than 3 per cent of people in China report being left-handed, despite the global average being closer to 10 per cent. Researchers think the difference is probably due to a continuing cultural stigma against left-handedness, which is less of an issue elsewhere, rather than genetics.
Hugo Spiers at University College London and his colleagues are overseeing a long-running study that assesses people’s ability to navigate using the mobile phone game Sea Hero Quest.
As part of this research, more than 400,000 … More

Nataliia Suietska/shutterstock
I LIVED happily without a microwave for 10 years, but, since acquiring one when I moved house last year, I have come to appreciate what a useful gadget it is. I have also realised that much of what I thought I knew about microwaves wasn’t quite right.
Microwave ovens work using electromagnetic waves, also called microwaves, with wavelengths of 12 centimetres or so – much longer than visible light, but shorter than most radio waves. Microwaves create an oscillating magnetic field that puts certain molecules in a spin: namely, molecules like water, which have positively and negatively charged portions. Anything … More

This piece of bone from 39,600 years ago has multiple puncture marks on it that seem to have been made by puncturing leatherF. d'Errico and L. Doyon
An analysis of a 39,600-year-old bone containing strange indentations claims it was used as a punch board for making holes in leather, revealing how Homo sapiens in Europe made clothes to help them survive cold climates at that time.
“We do not have much information about clothes because they’re perishable,” says Luc Doyon at the University of Bordeaux, France, who led the study. “They are an early technology we’re in the dark about.”
The bone, from the hip of a large mammal such as a horse or bison, was discovered at a site called Terrasses de la Riera dels Canyars near Barcelona, Spain. It has 28 puncture marks on its flat surface, including a linear sequence of 10 holes about 5 millimetres apart from each other, as well as other holes in more random positions.Advertisement

This pattern was “highly intriguing”, says Doyon, because it didn’t appear to be a decoration or to represent a counting tally – the usual explanations for deliberate patterns of lines or dots on prehistoric objects. Microscopic analysis revealed that the line of 10 indents was made by one tool and the other dots were made at different times by five different tools. “Why do we have different types of arrangements on the same bone?” says Doyon.
The researchers used an approach called experimental archaeology, in which you try out different ancient tools to see how marks were made. “We’re attempting to replicate the gestures that were used by prehistoric people to produce a specific modification on the bone,” says Doyon.
They found that the only way to recreate the type of indents on the Canyars bone was to knock a chisel-like stone tool called a burin through a thick hide, a technique called indirect percussion. The same method is still used by modern-day cobblers and in traditional societies to pierce leather.
The most likely explanation for the indents is that they were made during the manufacture or repair of leather items, say the researchers. After punching a hole in the animal hide, a thread could be pushed through the material with a pointed tool to make a tight seam, says Doyon.
“It’s a very significant discovery,” says Ian Gilligan at the University of Sydney, Australia. “We have no direct evidence for clothes in the Pleistocene, so finding any indirect evidence is valuable. The oldest surviving fragments of cloth in the world date from around 10,000 years ago.”
This discovery helps solve a mystery about the emergence of fitted clothing. Homo sapiens reached Europe around 42,000 years ago, yet eyed needles haven’t been found in this region from earlier than around 26,000 years ago and these aren’t strong enough to repeatedly puncture thick leather – raising the question of how these ancient people managed to make garments to fit them.

“The knowledge about making fitting clothing without bone needles is something we didn’t have access to before,” says Doyon.
“The location and date are interesting: southern Europe nearly 40,000 years ago,” says Gilligan. “That’s quite soon after the arrival of Homo sapiens, during some rapid cold swings in the climate. It’s when and where we’d expect our ancestors to need good clothes for protection.”
Doyon and his colleagues argue that this punch board marks a crucial cultural adaptation to climate change that helped modern humans expand to new regions.
The punch board was one of six artefacts found at the Canyars site, they say, and could have been part of a repair kit.

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