Archive for the ‘Behavioral science’ Category

Some clues about why male Guinea baboons fondle each other’s genitals

November 18th, 2018
Two baboons out for a walk carrying a third, infant baboon.

Enlarge / A baby Guinea baboon in its pre-diddling days goes for a ride. (credit: Michelle Bender / Flickr)

Male Guinea baboons have a curious habit. They will walk—or sometimes run—to another male baboon and say a quick hello in a very enthusiastic way: with a “mutual penis diddle”. Or sometimes it’s a quick mount from behind. Other times, they do a short dance-like “polonaise,” facing the same way, on their hind legs, hand on the other’s hip, and a few steps forward.

Clearly, this behavior needs an explanation. In some ways, it’s not all that much of a mystery: ritual greeting is actually fairly widespread among many primate species and takes many colorful forms. It's a behavior that's “common among males living in multi-male groups,” write the authors of a new paper exploring Guinea baboons’ greeting behavior.

So it’s no surprise that the Guinea baboons greet each other. But the intimacy of their behavior stands out. Unlike other species, where ritual greetings serve to cool down a tense or aggressive moment, for Guinea baboons, it seems to be more about keeping their social bonds strong.

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Posted in Behavioral science, Biology, cooperation, science | Comments (0)

Chimps have different cultural norms about friendliness, too

November 9th, 2018
The extent that chimps engage in social grooming is different between groups.

Enlarge / The extent that chimps engage in social grooming is different between groups. (credit: flickr user: Tambako The Jaguar)

Human cultures have widely varying norms when it comes to friendliness and politeness. Make accidental eye contact with a Londoner on public transport and suffer mutual horror, but go to South Africa and find yourself routinely embraced by complete strangers. For researchers studying human behavior, there’s a strong push to study a wider variety of different populations around the world in an effort to expand focus beyond rich westerners. But when it comes to animal behavior, differences between populations have come under less scrutiny.

A paper in PNAS this week explored differences in social behavior between four different populations of chimpanzees, finding that the groups had very different norms when it came to hanging out together and grooming one another. They point out that this means studying one population of chimps might not always be enough for accurate claims about the species as a whole.

Midwestern vs. New Yorker chimps

The Chimfunshi Wildlife Orphanage Trust in Zambia is an ideal place to investigate differences between chimpanzee groups. It's home to 120 chimpanzees, some of whom were wild-born but needed to be rescued and some of whom were born in the orphanage. The sanctuary has distinct populations separated from each other but all living in the same ecological environment.

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Posted in Behavioral science, Biology, primates, science | Comments (0)

Why does flat Earth belief still exist?

November 7th, 2018

Reality vs. belief about the shape of the Earth. Click for a full transcript.

There's no shortage of strange beliefs out there, and not all of them involve having a firm grip on reality. But it's truly bizarre to see one from the latter camp have a sudden surge in popularity and attention millenia after we knew it was wrong. But when it comes to the idea that the Earth is flat, centuries of accumulating evidence don't make much of a difference—its adherents have centuries of history of ignoring it, along with at least one not-nearly-as-famous-as-it-should-be instance of threatening a prominent scientist along the way.

That was Alfred Russell Wallace, one of the two co-developers of the theory of evolution.

This is our first try of a new video format where we look at controversies that, well, really shouldn't be controversial. While we may get back to Wallace and his theory, for the most part we're going to focus on cases where the motivation for the controversy is a bit less obvious. What drives people to believe in ideas that are blatantly, obviously divorced from reality? Or to reject ones that have a solid foundation of evidence?

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Posted in Behavioral science, Earth science, flat earth, Psychology, science | Comments (0)

Low-caste men in India cooperate like college students

November 7th, 2018
Cartoon of hunters with stags and hares

A diagram of the options in game theory's Stag Hunt. (credit: Wikimedia Commons)

In the Discourses on the Origin of Inequality, the political philosopher Jean-Jacques Rousseau imagines a hypothetical prehistoric Stag Hunt. Each hunter working alone can catch a hare, but hares aren’t very meaty. Working together a group can cooperate to take down a stag—but only if everyone is committed. If someone spots a hare and decides to go after it, the stag escapes and everyone else ends up hungry.

Economic studies in which university students in the US played simulated versions of the Stag Hunt indicated that at some point, pairs would realize that it was in both of their best interests to commit to hunting the stag and they would fall into “an efficient and cooperative equilibrium.” But it turns out that American university students are not a particularly representative subset of humanity and cannot necessarily grant deep insights into human nature. They are too WEIRD: Western, Educated, Industrial, Rich, and Developed.

When Indian men in the rural northern Indian state of Uttar Pradesh played the game, only low-caste men acted like the American students. High-caste men decidedly did not fall into an efficient cooperation.

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Posted in behavioral economics, Behavioral science, Biology, game theory, Human behavior, science | Comments (0)

Why figuring out what’s behind a big gender paradox won’t be easy

October 18th, 2018
A toy robot confronts a My Little Pony.

Enlarge / Pink vs. blue—innocent gender self-expression or material wealth creating more entrenched gender stereotypes? (credit: lambda's / flickr)

In Sweden, girls are just as likely to go to school and university as boys are. Women make up a greater proportion of the country’s professional and technical workers than any other country in the world. And their representation in the country’s politics is among the world’s best. But when it comes to personality tests, Swedish men and women are worlds apart.

Malaysia sits toward the opposite end of the scale: despite ranking among the world’s lowest for political empowerment of women and lagging when it comes to women’s health and survival, men and women end up looking similar in those same personality tests. What gives?


This fascinating finding—dubbed the gender-equality paradox—isn't new, but two recent papers report fresh details. In a paper published in Science today, Armin Falk and Johannes Hermle report that gender differences in preferences like risk-taking, patience, and trust were more exaggerated in wealthier and more gender-equal countries. And in a recent paper in the International Journal of Psychology, Erik Mac Giolla and Petri Kajonius provide more detail on the original paradox.

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Posted in Behavioral science, Biology, gender, science | Comments (0)

Gorillas that are great with kids are also luckier in love

October 18th, 2018
"Resting in contact", primatologist jargon for "getting a cuddle."

Enlarge / "Resting in contact", primatologist jargon for "getting a cuddle." (credit: Dian Fossey Gorilla Fund)

Cantsbee the gorilla was great with kids, which is why it struck gorilla researcher Stacy Rosenbaum as odd when he suddenly started grunting aggressively at his usual gaggle of baby gorilla sidekicks. Cantsbee seemed oddly annoyed by them tagging along behind.

“Cantsbee was always incredibly gentle,” says Rosenbaum. “He was never aggressive towards infants or humans. So the infants looked startled, not sure what to do.” Eventually they got the hint and moved off into the bushes to go around the grumpy Cantsbee, who then began displaying aggressively at Rosenbaum, too.

“I thought he was just having a really bad day,” she recalls. “But then I realized he was sitting next to a snare. It sent chills down my spine—I can’t say for sure, but it seems like he was protecting not just the infants, but me too.”

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Posted in Behavioral science, Biology, primates, science | Comments (0)

What do we actually know about the risks of screen time and digital media?

October 17th, 2018
Uh... this is fine, right?

Uh... this is fine, right? (credit: Getty Images)

“Yesterday after I wrote to you, I had an attack of asthma,” Marcel Proust wrote to his mother in 1901. “[It] obliged me to walk all doubled up and light anti-asthma cigarettes at every tobacconist’s I passed.”

While that sounds a bit crazy by 2018 standards, Proust was far from alone: “Medicated cigarettes marketed for respiratory complaints continued to be endorsed, and smoked, by doctors until well after the Second World War,” writes medical historian Mark Jackson.

Of course, tobacco eventually joined the list of treacherous substances once thought to be healthy and subsequently discovered to be harmful, keeping excellent company alongside radium and mercury. It's enough to make people constantly wonder what else might make it onto the list of friends turned foe. Could coffee be next? Processed meat?

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Posted in Behavioral science, Biology, Features, Game Violence, science | Comments (0)

Hearing voices? You might just be primed for it

August 27th, 2017

Enlarge (credit: flickr user: David Wood)

Hallucinations tend to be associated with psychosis, but the reality is more complicated than that. Some people who hear voices don’t suffer from other mental health problems, and the voices they hear aren’t distressing. These “non-clinical voice-hearers” provide an important opportunity to understand hallucinations without the complications of mental illness or medication.

A preliminary study published this week in the journal Brain reports that non-clinical voice-hearers were more likely to detect language in a recording of distorted speech. Voice-hearers also showed some different patterns in brain activation as they listened. The results could help to explain why some people are more likely to hear voices, as well as help to direct future research on the topic.

Hearing meaning in noise

Ben Alderson-Day, the lead author on the paper, is a psychologist at Durham University whose research focuses on auditory hallucinations. To investigate differences of perception in voice-hearers, Alderson-Day and his colleagues used sine-wave speech, which strips out some of the most vital acoustic properties of speech and leaves something that sounds kind of like a series of clicks and whistles. It’s possible to understand it—once you already know what it says, or once you’ve listened to quite a bit of sine-wave speech. (Listen to some examples here.)

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Posted in Behavioral science, Biology, Neuroscience, science | Comments (0)

Meta-analysis shows psychotherapy leads to long-term personality change

August 23rd, 2017

Enlarge / Even Lego clowns need therapy sometimes. (credit: Pascal / Flickr)

If you’ve ever wondered whether psychotherapy achieves meaningful, long-term change in a person’s life, wonder no more: combined evidence from multiple studies suggest that it does. A meta-analysis published recently in Psychological Bulletin reports that a variety of different therapeutic techniques results in positive changes to personality, especially when it comes to neuroticism, that last over a considerable period of time.

Personality is, as your intuition might tell you, relatively stable—people who start out gregarious and adventurous tend to stay gregarious and adventurous throughout their lives. Assessments of people’s personality traits taken at different times tend to agree pretty well with each other. But that doesn’t mean personality is static: personal growth, life experiences, and age all play their part, and people’s personalities do change somewhat throughout their lives—usually for the better.

An OCEAN of change

But it can be tricky to work out precisely what is being evaluated in measures of personality like the “Big Five” of Openness to experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism (“OCEAN”). Any personality questionnaire will come up with metrics that capture both someone’s stable, long-term tendencies (their traits), as well as how they are feeling in a given moment or phase in their life (their state). So, it’s not enough to find that therapy brings about personality changes—it’s also necessary to figure out how deep those changes go.

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Posted in Behavioral science, Biology, Psychology, science | Comments (0)

Tracking the spread of culture through folktales

August 13th, 2017

Enlarge (credit: Starz)

There’s a reason why the premise of American Gods is so alluring: the US is home to a wild and glorious mishmash of gods, folktales, and cultural heritage. One by one, groups from around the world picked up and landed on a new shore, bringing their stories with them.

The mere existence of certain tales can be revealing. They develop and mutate as they get passed from one group to the next, and the best stories are passed on more readily. Understanding the spread of folktales can help us understand cultural evolution more generally, and a paper in this week’s PNAS does just that by combining data on folktales with genetic, geographic, and linguistic information.

Researchers studying cultural evolution use biological evolution as a starting point for their ideas, but they also point out that clear and important differences separate the two types of evolution. The timescales, for instance, are often very different—cultural units can be transmitted between people of the same generation, while powerful ideas (like religions) can spread incredibly quickly and easily. A lot of work in cultural evolution is dedicated to trying to divine the mechanisms that underlie the spread of cultural ideas. How do people choose which ideas to adopt? And how does the spread of ideas compare to the spread of genes?

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Posted in Behavioral science, Biology, cultural evolution, science | Comments (0)