Category: Science

Teen brains show less activity in the regions associated with motivation, reveals a brain imaging study.

And adolescents may be more willing to engage in dangerous activities such as drink [sic] driving because this crucial part of their brain is under-developed, the US researchers suggest…Perhaps teens seek more extreme behaviours to achieve normal levels of stimulation in this brain region, he suggests.

Here is a longer discussion. I know I will receive hundreds, maybe even thousands, of angry emails from parents who cannot possibly believe this is true. But the reporting of science must progress, what can I say?

P.S. The skeptical may wish to note that the sample size is twelve teenagers and twelve adults for the study. But alas, no motivated teen wrote to tell me that.

Addendum: Randall Parker adds much more.

Perhaps microbes are riding on specks of dust.

A grain less than a tenth of a millimetre across would still be capable of carrying microscopic life, says Napier. And the pressure of sunlight can quickly blow grains this small out of the solar system. The same force might one day propel spacecraft through the cosmos.

Such a grain could travel about six light years from Earth in 70,000 years – far enough to reach other stars. We could be surrounded by a huge ‘biodisk’ of frozen organisms floating on grains of rock, says Napier, all of which can wander in and out of our solar system quite easily. “The solar system is as leaky as a sieve,” he says.

Earth should spread its seed widest when we pass through a giant molecular cloud, a mass of dusty material from which stars are born. This has happened about five times since life appeared on Earth.

Each time, Napier estimates about three billion trillion microbes passed from Earth into the cloud. The chances of some of these finding their way to an Earth-like planet are quite high, he says. A similar process could even explain how the Earth wound up hosting life in the first place, he adds.

Panspermia is one of my favorite words.

The ability to appreciate other people’s agony is achieved by the same parts of the brain that we use to experience pain for ourselves.

In other words, Adam Smith, a crazed bachelor writing in remote Scotland, and with no real means of making empirical measurements, nailed it. Some people’s introspection is better than others, here is Smith on sympathy. Read the full story about the recent work in neuroscience, here is another account. Here is a page for the researcher, Tania Singer.

…when women are at the most fertile point in their monthly cycle they tend to have a lower opinion of other women’s looks. And that’s not just because of mood swings. Menstrual phase had no effect on how the same women rated the looks of men, reports Maryanne Fisher of York University in Toronto, Canada.

Here is one version of the story. Here is another. Here is the home page of the researcher.

Over the weekend I’ve been gobbling up Brian Greene’s The Fabric of the Cosmos. I still don’t understand strings, branes, and how the known universe might be a projected hologram, but this book gets me further than any of the other popular science treatments I know. The author favors string theory and the idea of extra, hidden dimensions. He also discusses how we are on the verge of testing some of these exotic ideas. Recommended, especially if you find these ideas intriguing but have a hard time grasping them in intuitive terms.

Forthcoming research suggests that the family is a significant source of inequality:

…differences between families explain only 25 percent of the nation’s income inequality; the remaining 75 percent is explained by differences between siblings. More typical of the United States than President Bush and his brother Jeb, the governor of Florida, he suggests, are the White House’s previous tenant, Bill Clinton, and his half-brother, Roger, a college dropout, onetime cocaine dealer and failed musician. Or, for that matter, Jimmy Carter and his ne’er-do-well brother, Billy (emphasis added).

So what in the family matters? It is not birth order, here the analysis become quite intricate:

…his conclusions – that everything from parental job loss or divorce to race and family size can affect siblings differently – don’t lend themselves to catchy headlines, they arguably provide a more nuanced portrait of internal family dynamics than all-purpose explanations like birth order.

Some of his more provocative findings concern middle-borns. In families with three or more children, Mr. Conley says, middle offspring are less likely to receive financial support for their education and may do less well in school than their older and younger siblings. The chances that a second child will attend private school drop by 25 percent with the birth of a third, Mr. Conley found, and the likelihood that he or she will be held back a year increased severalfold. Unlike typical first- and last-borns, he reasons, middle children never experience family life as an only child; instead, they are forced to compete with their siblings for money and attention. (In this sense, he concedes, birth order does matter: not as a psychological variable but as a constraint on family resources.)

Other findings seem to confirm common-sense intuitions. According to Mr. Conley’s analysis, for example, women are more likely to be as successful as their brothers if their mothers worked outside the home. And, like the long-suffering George Bailey in “It’s a Wonderful Life,” the oldest child still at home at the time of a parental death or divorce is more likely than younger siblings to endure negative socioeconomic consequences as a result. Brothers and sisters may even experience race differently, he argues, since skin color can vary considerably within the same family.

So far it seems that the work is well-received. Here is the home page of the researcher, Dalton Conley, a remarkably prolific and rigorous scholar. Here is an earlier MR post on Horatio Alger and intergenerational mobility.

The (provisional) bottom line: Unhappy with your lot in life? It’s not the capitalist system or the Bush tax cuts, blame Mom and Dad. I’ll let you know more once the book arrives and I’ve read the whole thing.

What best predicts whether a marriage will last?

The crucial predictors, say the researchers, are the presence of facial expressions that accompany emotions such as contempt. Gottman says that just watching a couple and looking for this expression, described as a sideways pull of a corner of the mouth accompanied by rolling eyes, is enough to make a good guess about a couple’s suitability. “This is our best predictor,” he says. “Contempt is the sulphuric acid of love.”

We are told that the entire model has a 94 percent success rate in predicting divorce.

Here is some positive advice for Valentine’s Day:

Gottman may also have stumbled across the secret of a lasting relationship – simply ignore the nasty comments from your partner. He says that courting couples tend to ignore negative statements and pay more attention to positive remarks. Once married, this trend often reverses, although couples that remain together into their sixties retain this outlook.

How about gay couples?

…gay and lesbian couples, as well as heterosexual couples that do not marry, hold on to the positive value of courtship better than straight partners who get hitched, he says.

For more information, read The Mathematics of Marriage: Dynamic Nonlinear Models. Are they joking with that title?

Relative to email, that is. Why? Email leaves a permanent record and you are afraid of getting caught in your lies.

Jeff Hancock of Cornell University in Ithaca, New York, asked 30 students to keep a communications diary for a week. In it they noted the number of conversations or email exchanges they had lasting more than 10 minutes, and confessed to how many lies they told.

Hancock then worked out the number of lies per conversation for each medium. He found that lies made up 14 per cent of emails, 21 per cent of instant messages, 27 per cent of face-to-face interactions and a whopping 37 per cent of phone calls.

That’s a lot of lying. Here is the full story.

Carry a lie detector in your pocket:

The Love Detector is based on layered voice analysis, a system that was developed for security work by Nemesysco, an Israeli company, and adapted for personal use by V Worldwide, the international distributor.

The Love Detector relies on a simplified form of the technology, said Richard Parton, chief executive of V Worldwide. The security version applies 8,000 algorithms to 129 parameters of a speaking voice, assessing, among other things, levels of emotion, embarrassment and concentration as well as whether what is said reflects certainty, uncertainty or outright lies.

When this reporter tried it informally, both in person and over the phone, the results were arguably accurate; the software detected the split in my attention as I took notes, though it misinterpreted my skepticism about the product as condescension.

Buy one here.

Some versions of the new product will put James Bond to shame:

Later this year V plans to introduce a simplified version built into sunglasses, with light-emitting diodes to signal emotional intensity and truth or falsehood.

Here is one article about the product. Here is the whole story. The article notes that many people will use the product to assess their own emotions, not just the person they are trying to court.

Picture yourself watching a one-minute video of two teams of three players each. One team wears white shirts and the other black shirts, and the members move around one another in a small room tossing two basketballs. Your task is to count the number of passes made by the white team – not easy given the weaving movement of the players. Unexpectedly, after 35 seconds a gorilla enteres the room, walks directly through the farrago of bodies, thumps his chest and, nine seconds later, exits. Would you see the gorilla?

Fifty percent of all observers do not see the gorilla.

This is called inattentional blindness, the link offers some further examples and tests. The bottom line: if you are concentrating on one static task, you often fail to notice dynamic movement. This is one reason why you should not drive and talk on your cell phone at the same time.

The quotation is from the March issue of Scientific American. Here is the the original research. Here are some additional studies, also look here. Here is a page of video exercises, although now you know what and who to look for.

The bottom line for economics? Neither investors nor voters need be rational in procedural terms. Searching more does not guarantee a better outcome. An “obvious” bubble can catch large numbers of investors unaware. And we, as voters, can fixate on some aspects of candidates and miss entirely their most important qualities.

Sports fans are not the only ones to celebrate a win with a rousing tune – a chirpy African bird does the same, researchers have revealed.

Mate pairs of the tropical boubou belt out their special victory song after they have deterred would-be invaders from their territory, suggest Ulmar Grafe and Johannes Bitz at the University of Würzburg, Germany.

The discovery was made by accident, the scientists happily admit. They were investigating the birds’ musical repertoire in the Ivory Coast when they noticed that whenever they packed up their equipment and left the bird territories, the birds would trill a particular tune.

To investigate this further, Grafe and Bitz then tried broadcasting recordings of the duets commonly used by boubous in territorial confrontations. They found most mate pairs that stood their ground against the recorded intruders burst into song shortly after the tape was switched off.

“There’s a whole neighbourhood of birds listening into these conflicts, so it’s important to advertise a victory,” says Grafe, a behavioural ecologist. “We think it’s not only to let the loser know they’ve lost, but to let others know that one has been victorious – it serves to lessen further conflicts over territory.”

He adds that there are few animals which vocally celebrate a win in this way. And the tropical boubou is the first documented to perform a duet. “It’s sort of like a rugby team, a whole team display – I don’t know of any other animal example,” he told New Scientist.

I’ll really be impressed when they can hum “We Will Rock You.”

Here is the full story. Thanks to Spitbull.com for the pointer.

They use the roads, it turns out, not just the sun.

Researchers at Oxford University spent 10 years studying homing pigeons using Global Positioning System (GPS) satellites and were stunned to find the birds often don’t navigate by taking bearing from the sun.

Instead they fly along motorways, turn at junctions and even go around roundabouts, adding miles to their journeys, British newspapers reported.

“It is striking to see the pigeons fly straight down the A34 Oxford bypass, and then sharply curve off at the traffic lights before curving off again at the roundabout,” he said.

Guilford said pigeons use their own navigational system when doing long-distance trips or when a bird does a journey for the first time.

But when they have flown a journey more than once they home in on an habitual route home.

“In short it looks like it is mentally easier for a bird to fly down a road…they are just making their journey as simple as possible.”

For a given amount of pressure, it hurts more when a man is making you feel bad:

Participants placed a finger in a clamp which was tightened using a pressure gauge until they reported feeling pain. Both men and women appeared to feel pain more quickly if the person turning the clamp was a man.

Previous studies have shown that men report feeling less pain in front of a female experimenters – but this was put down to their wanting to appear more macho.

David Williams, who carried out the study at the University of Westminster in the UK, says his findings contradict this assumption. Williams suggests that the subjects of his study may be socially conditioned to expect men to be more likely to inflict harm. The effect, “is likely to be a result of what participants subconsciously expect, based on socially acquired gender stereotypes,” he says.

We are susceptible to the power of suggestion in other ways as well:

The study also shows that a person’s surroundings can affect their sensitivity to pain. Objects that might be associated with suffering – such as a chart showing wounds or a poster related to blood donations – were found to make the participants report feeling pain more readily.

Here is the full story, here is the researcher.

The bottom line? No, it is not all in your head. Nonetheless a stoic attitude may help you endure discomfort. Furthermore we seem programmed to think that men are the bad guys. They usually are.

Some people may be aware that a scene they are looking at has changed without being able to identify what that change is. This could be a newly discovered mode of conscious visual perception, according to the psychologist who discovered it. He has dubbed the phenomenon “mindsight”.

Ronald Rensink, based at the University of British Columbia in Canada, showed 40 people a series of photographic images flickering on a computer screen. Each image was shown for around a quarter of a second and followed by a brief blank grey screen. Sometimes the image would remain the same throughout the trial; in other trials, after a time the initial image would be alternated with a subtly different one.

n trials where the researchers manipulated the image, around a third of the people tested reported feeling that the image had changed before they could identify what the change was. In control trials, the same people were confident that no change had occurred. The response to a change in image and control trials was reliably different.

Our visual system can produce a strong gut feeling that something has changed, Rensink says, even if we cannot visualise that change in our minds and cannot say what was altered or where the alteration occurred.

Here is the full story. The bottom line? Maybe somebody really is following you, and subtly changing small items in your environment.