Category: Science


There is no doubt that laughter is a social activity. “Laughter evolved as a signal to others – it almost disappears when we are alone,” says Robert Provine, a neuroscientist at the University of Maryland the author of Laughter: A Scientific Investigation…most laughter comes in polite response to everyday remarks such as “Must be going”, rather anything remotely funny. The idea that laughter works as a kind of social glue fits with some other other observations. A baby’s first giggle comes at around three or four months, which also happens to be the time the baby starts to recognise individual faces. And the way we laugh depends on the company we’re keeping. Men tend to laugh longer and harder when they are with other men, perhaps as a way of bonding. Women tend to laugh more [almost fifty percent more] and at a higher pitch when men are present, possibly indicating flirtation or even submission.

Here is a brief on-line summary of Provine’s ideas. Oh yes, by the way, when the boss laughs, everyone laughs. Note also that smiling may be easier to fake than genuine laughter, which would suggest one reason why laughter evolved to signal social bonds.

And how about tickling? It is, according to Provine, the origin of laughter and a way for two individuals to signal that they trust each other. This seems excessively functional to a skeptical economist like myself. By the way I hate being tickled.

Thanks to Robin Hanson for the pointer to the 20 December issue of New Scientist, from which the opening quotation is taken.

Fountain of youth?

Scientists are making some progress on this difficult problem:

Human embryonic stem (ES) cells can give rise to almost all of the body’s different cell types. They could eventually provide patients with replacement tissues – but there are some roadblocks that currently prevent researchers from putting the cells into patients’ bodies. One problem is that scientists don’t yet know how to control the cells’ transformations into other types. Another is that the cells cannot be grown without help from mouse cells, which means that they could be contaminated with mouse proteins. Ali Brivanlou of Rockefeller University in New York says that he and his colleagues may have found a partial solution to these problems. Brivanlou treated ES cells with a chemical, nicknamed BIO, from a sea snail.

Being 41, I don’t expect to enjoy the fruits of this research. But today’s children may live for a very long time indeed. That being said, my chance is not zero, so the return to exercise and good eating just went up.

Luck and entrepreneurship

If you have been a lucky person in the past, good things will happen to you in the future. Or is it enough simply to think that you were lucky in the past? Relaxed, confident people may find it easier to discover subsequent opportunities. Read about some interesting experiments on the lucky. The bottom line: “Unlucky people are generally more tense than lucky people, and this anxiety disrupts their ability to notice the unexpected.”

And what about practical advice? It is suggested that visualizing yourself as lucky, in advance of a challenge, will improve the course of events.

Should you wait or go?

You are waiting in line, and must decide whether or not to stick it out or bolt. How do you choose?

Most people look back and see how many people are behind them in line. If the line behind them is long, they tend to stay in line and wait. And if they do quit, they are most likely to quit in the first three minutes.

Making this kind of comparison could be economically rational. A long line means that if and when you have to come back, you will be forced to wait anyway. So why not just get the waiting over with? (Note that the researchers try to control for this effect, although imperfectly.) A long line also suggests that many other people value the good or service, which again implies that waiting is worthwhile.

But that is not the primary hypothesis of the researchers, nor is it how I think. When I look back and see many people behind me, I feel that my lot in this matter is not so bad, and that I should stick it out. So I do.

The short article on this research is from the December issue of Psychology Today, but the article itself is not yet on-line. Here is the home page of one of the researchers, including a full citation to the article in Journal of Consumer Research. Here is a on-line summary of the work.

What are the best Christmas gifts?

Experiences, not possessions. Concerts and travel are remembered for longer than clothes and jewelry. The result is robust to different ages and groups, but tends to be strongest for high-income individuals. Here is the full story, here is another summary. Here is the original paper. The home page of Van Boven, one of the researchers, offers many interesting papers on human psychology.


Often I love the idea of science fiction more than science fiction itself. I’ve read most of the classics, and I am left with junk at the relevant margin. But lately I’ve been wrapped up in Stephen Baxter’s Evolution, published earlier this year. The book, spanning almost six hundred pages, tells the story of evolution from the point of view of our genes. To be sure, the book would be easy to satirize. It has no central characters, covers 65 million years of history, and frequently presents how different animals think [sic] about copulation. OK, that doesn’t sound like an obvious recipe for success but Baxter pulls it off to a surprising degree. The treatment is reminiscent of H.G. Wells or Olaf Stapledon, a particular favorite of mine. If you, like me, are desperate for science fiction that is actually intellectually stimulating, give this book a try. We are told, by the way, that the capacity to believe contradictory ideas is what makes human beings special.

Baxter pushes the Stephen Jay Gould line that the results of evolution are highly dependent on small accidents. For a contrasting point of view, from a more scientific front, see Life’s Solution: Inevitable Humans in a Lonely Universe. The author Simon Conway Morris argues that the path of evolution is much less contingent than is commonly believed. He points to numerous biological structures, such as the eye, that have evolved repeatedly under different guises. Here is one brief summary, here is a longer and more critical presentation. Life’s Solution, which occasionally verges on theology, should be read with a critical eye. Nonetheless if you feel you have read all the good popular books on evolutionary biology, here is a text with something new and provocative.

Earthlike planets may be common in the universe

Read Futurepundit on this topic. This news increases the expected well-being out there in the universe, but probably lowers the expected welfare of mankind. Visiting aliens could be a boon or a disaster but I am risk-averse in this capacity. Neither my juvenile love for science fiction nor my general optimism make me wish to live to see alien visitation. While earth institutions are far from efficient, they could be much worse. Right now the dominant technological power, the United States, is relatively benevolent by the standards of world history. Technologically superior aliens would upset this balance and could leave too much power in the wrong hands.

This whole news about planets only raises the question anew: Where are they? One possibility is that civilizations simply do not last very long on a cosmic time scale. If intelligent life has evolved elsewhere in the universe, most of the time it has expired before having a chance to contact us. If the window of opportunity is sufficienly small, it would help explain why we do not receive signals from other civilizations.

The research also shows that the nature of Jupiter’s orbit may be responsible for intelligent life on earth:

The simulations show that the amount of water on terrestrial, or Earthlike, planets could be greatly influenced by outer gas giant planets like Jupiter.

“The more eccentric giant planet orbits result in drier terrestrial planets,” Raymond said. “Conversely, more circular giant planet orbits mean wetter terrestrial planets.”

In the case of our solar system, Jupiter’s orbit is slightly elliptical, which could explain why Earth is 80 percent covered by oceans rather than being bone dry or completely covered in water miles deep.

This points to another reason why the aliens have not come. The existence of intelligent life requires a very large number of favorable coincident factors, perhaps larger than we have realized to date. But read Brad DeLong on the Fermi paradox, which suggests a large number of intelligent civilizations out there in the universe, even once we account for all the improbabilities.

Bad Science Poisons Our Children’s Brains

The Natural Resources Defense Council has got mercury on its mind. They write, “Mercury Poisons Our Children’s Brains” explaining:

Mercury is a potent neurotoxin that, like lead, especially threatens the brains and nervous systems of fetuses and young children. A number of neurological diseases and problems are linked to mercury exposure, including learning and attention disabilities — which are a growing problem — and mental retardation. Mercury also might be linked to the recent increase in autism, Parkinson’s disease and Alzheimer’s disease…one in every 12 women of childbearing age has mercury in her blood above the EPA “safe” level…Toxic mercury emissions from power plants put 300,000 newborns each year at risk for neurological impairment.”

Frightening isn’t it? Lets take a closer look before sending the NRDC a check. How was the EPA’s safe-level arrived at? There are three major studies of mercury and neurological impairment in children due to consumption of contaminated fish. One study found no effect, one was ambiguous, the last found some mild impairment (You would never notice the impairment on an individual level and can detect it only in a large sample. Not to be ignored if it exists, but we are not talking about Downs children). To be on the safe side, the EPA focused on the one study that found an effect. Within that one study there was some uncertainty about how much mercury caused a problem so the EPA took that study’s lower bound (the lower bound of the 95 confidence interval for the statisticians in the audience.) Finally, to really be on the safe side, they divided the lower bound by ten!

Now notice how the charlatans at the NRDC twist a number of true facts to make a big lie. It is true that mercury can cause neurological impairment and it is true that 8% of women have blood mercury greater than the EPA safe level but you would never learn from the NRDC that the EPA safe level is more than ten times smaller than levels that have ever been found to cause mild impairment and that even the existence of such impairment is open to question. Throw in a few warnings about how learning disabilities are a “growing problem” and, for all the readers who don’t have children, don’t forget to mention the “recent increase” in Parkinson’s and Alzheimers and you have a perfect example of advertising masquerading as science. (Ever notice how many public interest groups sound like used car salesmen? Sale! Sale! Sale! Buy now before its too late!)

The NRDC wants emission levels cut by 90% in three years, an approach that would cost billions of dollars. The Bush administration wants to cut levels by 30% over the same time period, which would have a marginal cost of virtually nothing because of other regulations scheduled to take effect in anycase, and by 70% over a somewhat longer time frame. Naturally, the NRDC thinks this is evil. This time, I agree with the administration.

I have cribbed from CEIs Joel Schwartz and AEIs Lutter and Irwin.

The future of dieting

Economist Ed Glaeser, a trim man, is a vigorous partisan of the Atkins Diet. Nonetheless he argues that McDonald’s brings social benefits, not social costs:

Glaeser’s rationale for suggesting that convenience foods are a social good is that, to judge from consumer behavior in the marketplace, people seem to prefer saving time to being thinner. And in economics, by and large, getting what you want is a good thing. Glaeser notes that until relatively recently, cheaper food (in terms of money as well as time) made us taller and healthier. Only in the past 25 years or so have diminishing returns set in.

Now that less is more when it comes to increased calorie intake, Glaeser expects the marketplace to correct the excesses he attributes to self-control problems. For one thing, food technology can’t advance much farther, “short of direct injection,” whereas weight-loss technology is only in its infancy, with vast room to grow. Glaeser can understand the need for regulation in the schools, or if food companies are misleading people. But he says: “I don’t think anybody ate at McDonald’s and thought it was good for them. I take a dim view of these lawsuits.”

Thanks to for the link, and Daniel Akst for the article itself. See also Alex’s post on Three Oreo Cookies.

Impressing a woman vs. impressing a man

Dr. Rangel tells us how to impress a woman:

Wine her, Dine her, Call her, Hug her, Support her, Hold her, Surprise her, Compliment her, Smile at her, Listen to her, Laugh with her, Cry with her, Romance her, Encourage her, Believe in her, Pray with her, Pray for her, Cuddle with her, Shop with her, Give her jewelry, Buy her flowers, Hold her hand, Write love letters to her, Go to the end of the Earth and back again for her.

How to impress a man;

Show up naked… Bring food… Don’t block the TV.

OK, this is clever, but it is not exactly correct either. One good way to impress a woman is to do something to impress other men (and women). The famous attract women in great droves. And if you want to impress a man, help him think that he has high relative status. “Don’t block the TV” is not nearly as good as being the kind of woman who, through whatever means, can impress other men (and women), and thus reflect favorably upon the man.

Ralph Nader and the regulation of neuroscience

Ralph Nader’s Commercial Alert group seeks to restrict or prohibit commercial research into neuroscience. You might recall that researchers at Emory are hard at work on this problem:

Neuromarketing research uses a magnetic resonance imaging machine, or MRI, to determine which parts of the brain react to different types of advertising in an effort to help marketers develop more effective marketing techniques for selling their products or services.

The critics charge that the research is directed at finding a “buy button” in the mind. Critics also raise the specter of mind control and the loss of individual autonomy. Commercial Alert makes the following threat:

“It is wrong to use medical research for marketing instead of healing,” Ruskin said. “If Emory University doesn’t stop this immediately, we will do everything in our power to shut down Emory’s federal funding.”

My take: The neuroscience techniques remain unproven, but in the meantime corporations are subsidizing an important science. Many of our most significant scientific discoveries have been by accident, when people were looking for some other result altogether. The support for research may well have a real long-run payoff.

Furthermore the worries are overblown. Let’s say we found such a buy button and that corporations could use that knowledge in their ads. Would it really shift the marketing balance of power in favor of sellers? Over time I would expect buyers to compensate, as the knowledge would not stay secret for very long. We could imagine lists of products that were sold by manipulative techniques, and customers would know to stay away from such products. A technological arms race would be set off. We could imagine private entrepreneurs selling “counter-persuasion” techniques to customers, perhaps in the form of drugs, warning buzzers, or counter-subliminal images flashed into your eyeglasses (the latter product is already under development!). Or how about programming the microchip credit card embedded in your arm to discourage or prevent such manipulation-induced purchases? Or how about if consumers use neuroscience to learn how to be truly happy staying at home and cultivating their gardens?

Sellers seem to have the biggest advantage when manipulation techniques are less than transparent. So neuroscience research into buyer behavior may be a classic prisoner’s dilemma problem. Various sellers may pursue such knowledge, hoping to get a leg up on the competition. The long-run result may be an evaporation of business advantage and an empowering of consumers.

Thanks to Kevin McCabe for the pointer on this issue, check out his neuroeconomics blog.

How to conserve flu vaccine

The flu vaccine is now running very scarce, you can wait for weeks and there is no guarantee of getting it at all. Most of the supplies are already in the hands of doctors. Note also the following:

Random immunization is almost useless because, for many viruses, more than 95% of the population must be vaccinated to prevent the disease’s spread.

But things are not as grim as they might sound. First:

An alternative to the flu shot is FluMist, a more expensive inhaled version of the vaccine, which is recommended for healthy people between the ages of 5 and 49. There are about 4 million doses available of FluMist, health officials said.

Although those below 5 and over 49 are the at-risk groups, they are less likely to catch the flu if the rest of us are healthy.

Second, we could administer flu shots more wisely by targeting superspreaders, here is one proposal:

Reuven Cohen of Bar-Ilan University in Israel and his colleagues propose a simple modification of random vaccination that is more effective, according to their computer simulations. The idea is to randomly choose, say, 20% of the individuals and ask them to name one acquaintance; then vaccinate those acquaintances. Potential super-spreaders have such a large number of acquaintances that they are very likely to be named at least once, the researchers found. On the other hand, the super-spreaders are so few in number that the random 20% of individuals is unlikely to include many of them.

Using the team’s vaccination strategy, a disease can be stopped by vaccinating less than 20% of the individuals, in some cases, according to their computer model of a human population. The method can also be tweaked: if a larger sample is asked for names, and those named twice are vaccinated, the total number of vaccinations required can be even lower.

The trick may be getting these people to take the shots, but surely economists can come up with a useful incentives scheme for that, I would prefer a subsidy over a tax.

Beware X-Rays

I am always pleased when one of my crank folk medicine theories is proven to be true, or at least possible. It turns out that low-level X-Rays might be much more dangerous than we had thought. In fact they might even be more dangerous than high-level X-Rays, because the cells do not repair themselves in the same way. Keep this in mind when you visit the dentist, I haven’t let them do this to me for six years now, despite continual entreaties and guarantees that it is safe. I picked this fact up from the January 2004 issues of Discover magazine, which covers the 100 biggest science stories of the year, go buy a copy and catch up on a year’s worth of science reading, not yet on-line.