Category: Science

You operate the brakes, the computer controls the car and fits it into the parking space. This is now a $2,200 option, available on some Toyotas in Japan. Here is the full account. Eighty percent of the eligible customers are opting for this package. My view? If you can’t parallel park, I bet you screw up on the operation of the machine.

Mark A. Walker and John C. Wooders, economists at the University of Arizona, recently studied old videotapes of tennis matches involving stars like Bjorn Borg, Ivan Lendl and Pete Sampras. The economists looked at the serves in each match to see how well players randomly altered playing the ball to an opponent’s forehand or backhand.

Many people do poorly on similar tests when they are conducted in a laboratory. Ask somebody to write down a list of hypothetical coin-flip outcomes, for example, and the result will probably contain too few streaks of heads or tails. Because people know that the overall odds are 50-50, they underestimate how often three straight tails or four straight heads turn up.

But professional tennis players realize, on some level, that their opponent will have an advantage if he knows that a serve to the forehand is likely to be followed by one to the backhand. They do a relatively good job of mixing serves, though still not as randomly as a computer program would, Professors Walker and Wooders reported in a 2001 paper.

Controlled experiments yield similar results, read this account from The New York Times.

Here is the bottom line:

The more uncertainty that people face – be it caused by wind on a tennis court, snow on a football field or darkness on a country highway – the more they make decisions based on their subconscious memory and the less they depend on what they see.

Related research by Doru Cojoc of Clemson shows that chess players play mixed strategies to keep their opponents off balance. Furthermore they are more likely to play such sophisticated strategies, the higher the rewards on the line.

By the way, even plants seem to perform implicit calculations when they breathe, read this recent account. Armen Alchian, of course, once postulated a similar conjecture, namely that plants maximize sunlight without any conscious awareness of such a process.

Evidence is building for hormesis, the theory that suggests that moderate doses of bad things like radiation and toxins can improve health. Interestingly, much of the evidence has been around for a long time but it has been ignored because the focus was on proving the harm that toxins can cause and because low-dose effects are, by their nature, harder to identify so positive effects at low doses were typically discounted. Edward J. Calabrese of the University of Massachusetts at Amherst, however, has collected thousands of already published examples and is conducting original research of his own into hormesis. Other researchers are beginning to take notice. Hormesis is controversial, however, as you might imagine from this bombshell:

Calabrese suspects that in many cases, the benefits of hormesis may occur at levels higher than the recommended safe doses for humans.

Hormesis is a similar idea to the hygiene hypothesis (more here) which asserts that “reduced microbial exposure because of increased sanitation and cleaner lifestyles has facilitated the rise in asthma and allergic disease in the Western world.” (The mechanisms of the two effects appear quite different, however.)

Many smokers manage to smoke fewer cigarettes. The problem is that they often puff all that much harder. In the long run they may not end up much healthier, read this account. By the way, Sam Peltzman has studied this phenomenon more generally. We can do things to make people safer, but they respond by taking more risks. Thanks to Jon Klick for this latter link.

The evidence suggests that fathers prefer boys over girls. For instance a couple is more likely to stay married when they have a boy rather than a girl. Here is my earlier summary of the research.

At the same time couples are far more likely to adopt girls rather than boys? How can this be?

A recent Slate article offers some figures:

Numbers vary, but it’s pretty safe to say that somewhere between 70 percent and 90 percent of parents looking to adopt register some preference for a girl with an agency. It doesn’t matter if they’re adopting from China, where girls far outnumber boys; from Russia, where the numbers are about even; or from Cambodia, where there is typically a glut of orphan boys and a paucity of girls. Everywhere, demand tends to favor the feminine.

Steven Landsburg had suggested an adverse selection argument. Yes boys are favored but if a boy is put up for adoption, you can figure there is something wrong with the boy, for precisely that reason.

Or perhaps it is easier to nurture girls, and the nurturing motive may be central to the adoption decision. It also may be the case that mothers prefer girls and mothers also drive adoptions:

“The extent to which women are the driving force in most adoptions is probably a factor,” he says. “It’s usually true that the women are filling out the paperwork, going to the conferences, the support groups.” He adds, “If I speak at a conference–whether it’s on adoption or family issues–at least 80 to 90 percent of any of these audiences are women.”

My take: Having a boy is a riskier investment than having a girl. The risk rises dramatically with adoptions, given the associated genetic uncertainty. Males are more likely to have genetic roots for criminality and mental illness. So if you don’t know much about the parents, better to play it safe and opt for a girl.

At first, I was merely uninspired by President Bush’s plan to resend men to the moon and then on to Mars (Here are better ideas from MR readers). Now I am upset and saddened. The Hubble telescope is one of the great achievements of the recent space program, especially after the amazing in-space eyeglass repair job. Data from the Hubble have helped us to understand the universe in all its awesomeness and yet the Hubble will now die an early death because of the budget shift.

Here is Hubble’s picture of the eye of Sauron:

Just kidding about the last one, it’s MyCn18, a young planetary nebula, the glowing relic of a dying, Sun-like star.

This is the Cartwheel Galaxy, located 500 million light-years from Earth in the constellation Sculptor.

Here are two galaxies, NGC 2207, is on the left and IC 2163 on the right that are slowly colliding.

Here are more Hubble pictures.

John Gottman has spent decades studying how married couples interact. His most striking finding is the tendency of couples at risk of divorce to have markedly different interaction styles. His recent book, The Mathematics of Marriage, summarizes his observations of married couples and presents a parsimonious model of marriage (see here for Slate’s review). The highlight of the research is that couples where the dominant mode of interaction includes criticism, contempt, defensiveness and stonewalling are very, very likely to divorce. Successful marriages involve a great deal of mending and reworking of the relationship. The mathematics links some theories about emotions and interaction to this observed pattern.

What I find interesting is the implication for thinking about politics. Let’s assume that political order is a sort of “marriage” between state and citizen. At least from the perspective of the citizen, it’s a relationship that can be broken, if warranted. This is a premise of many normative theories of revolution – the citizens have a right to a new government if they feel the written and unwritten rules have been violated. Unfortunately, what we know about exactly how this happens – moving to abandon the social contract – is sketchy at best, although political scientists and sociologists have a hunch that it involves some combination of repression of the population and a de-legitimizing of the government, which itself might have multiple causes.

Gottman’s approach to studying relationships offers a useful way to think about these issues. Gottman’s point is that there may be varying sources of the emotions that destroy marriages, but the road to divorce usually starts in the same place – once spouses have learned certain interaction strategies, they create hard to change feedback loops. Similarly, governments and populations that learn certain strategies for interacting with each other probably set up hard to break cycles leading to long term stability or perpetual crisis. The nice thing about Gottman’s analysis of marriage is that the math predicts stability or decline, and not much in between – a non-trivial prediction. The same prediction for states is that states tend to be on a tough to change road to constant crisis (like in Africa and the Middle East) or stability (like in the US). Switches from one path to the other should be infrequent and difficult, which seems to describe the world pretty well.

Read the ever-impressive Randall Parker over at Futurepundit.com. Here is a quotation from one of his links:

Lahn and his colleagues found that the ASPM gene showed clear evidence of changes accelerated by evolutionary pressure in the lineage leading to humans, and the acceleration is most prominent in recent human evolution after humans parted way from chimpanzees.

“In our work, we have looked at evolution of a large number of genes, and in the vast number of cases, we see only weak signatures of adaptive changes,” said Lahn. “So, I was quite surprised to see that this one gene shows such strong and unambiguous signatures of adaptive evolution – more so than most other genes we’ve studied.”

By contrast, the researchers’ analyses of the ASPM gene in the more primitive monkeys and in cows, sheep, cats, dogs, mice and rats, showed no accelerated evolutionary change. “The fact that we see this accelerated evolution of ASPM specifically in the primate lineage leading to humans, and not in these other mammals, makes a good case that the human lineage is special,” said Lahn.

The bottom line: The plausibility of the view that human beings are special has just gone up.

Parker is one of the most rigorous and versatile writers in the blogosphere, here is his recent account of our greater ability to predict earthquakes.

Addendum: Read this article on exactly why monkeys have trouble with human language.

Sometimes you share just to shut people up:

Stevens [the researcher] placed chimpanzees (Pan troglodytes) or squirrel monkeys (Saimiri boliviensis) in a cage and provided them with a meal of fruit. In an adjoining cage was a hungry member of the same species.

The primates rarely passed food through the cage to their hungry mate next door. But if the partition was opened – giving the hungry animal the chance to beg, steal or fight for food – sharing was common.

It is analogous to a parent buying a child a toy just to shut them up, says Stevens. “It’s a selfish way to stop the constant pestering,” he says.

Intriguingly, hungry chimps harassed their neighbour more when the food was cut into small chunks. This could reflect the fact that a beggar is more likely to get a handout if it doesn’t seriously deplete the donor’s stash.

This form of ‘strategic begging’ could help scroungers find success by setting their sights low, Stevens speculates. “It’s like a kid saying: ‘Can I have four cookies? Ok, how about one?’,” he says. Likewise, most street-corner beggars ask passers-by for nothing more than their small change.

Here is the full story. Right now the link to the original paper is not working.

It is bad for rats, or so it seems:

…new research published in the Proceedings of the National Academy of Science shows that caution can actually kill you. Sonia Cavigelli and Martha McClintock of the Department of Psychology and Institute for Mind and Biology at the University of Chicago found in a recent experiment that individuals who fear novelty–a condition scientists have named “neophobia”–are likelier to die at an earlier age than those who are unafraid of change. It is the first time, says Cavigelli, that a study has demonstrated that an emotional trait that shows up in infancy can shorten life span.

For this research, Cavigelli and McClintock followed the lives and fortunes of pairs of rat brothers for several years. The scientists chose their subjects by first establishing which of the rats were neophobic. To do this, they placed the young rats inside a bowl in a small room. Objects the rats hadn’t seen before–a rock, a metal box, and a plastic tunnel–were placed in each corner of the room. The rats the scientists deemed neophobic either stayed hunkered down in the bowl or left it only hesitantly, with hunched backs, stilted walks, and bristling fur. The rats who left the bowl quickly to explore the room and the various unfamiliar objects were dubbed neophilic.

And the results? These risk-averse rats showed a consistent pattern of stress throughout their lives and died at earlier ages. What does this mean for people?

A number of parallels exist between humans and their rat surrogates. Neophobia shows up in human infants as early as 14 months of age, and like the rats, fearful children have a faster and stronger hormonal response than children who are not afraid of new situations. It’s also been shown that if you are neophobic at a young age, you tend to remain that way throughout childhood. Cavigelli suggests, however, that individuals may develop strategies to avoid the negative effects of neophobia. “If you are a neophobic-type person, you might avoid any novel situations thereby minimizing that stress,” she says. Staying away from stressful situations could be a form of “self-medication.”…The wear and tear of stress hormones can cause neophobes to get sick more quickly, suggests Cavigelli. So if you know you’re a neophobe–and therefore more vulnerable to any bug going around–you might want to be seek medical intervention promptly in the case of illness.

Although it looks like the neophiles have an unfair advantage, they may not have it as good as it seems. In the experiment, Cavigelli and McClintock played God by controlling the environment of their subjects and essentially creating a safe universe where being brave didn’t get you into trouble. But real life, with its car accidents, plane crashes, and human predators does not always reward the fearless. Human neophiles might also have longer lives if we were all just rats in a cage.

The researchers suggest that it makes evolutionary sense for mothers to have emotionally diverse litters. In other words, there is an evolutionary reason why some but not all teenagers can act like such foolish idiots. See Slate.com for the full story.

Read here for the latest scientific discovery.

Has the Poincare Conjecture been solved? Possibly. Read this recent news report about a new proof by an obscure Russian loner, Grisha Perelman. The Conjecture is one of the famous Millennium Problems in mathematics.

“This is arguably the most famous unsolved problem in math and has been for some time,” said Bruce Kleiner, a University of Michigan math professor reviewing Perelman’s work.

Here is the clearest statement I can find of what the whole thing means:

To solve it, one would have to prove something that no one seriously doubts: that, just as there is only one way to bend a two-dimensional plane into a shape without holes — the sphere — there is likewise only one way to bend three-dimensional space into a shape that has no holes. Though abstract, the conjecture has powerful practical implications: Solve it and you may be able to describe the shape of the universe.

Or try this:

[the] work has huge implications for our understanding of partial differential equations. PDEs (as they are known in the trade) are the mainstay of physics and engineering. Mazur notes that physicists and engineers use PDEs to model everything from the flow of water to the buildup of heat in aircraft engines. “I would expect this work to have enormous applications in many fields of science,” he says.

There may also be applications for scientists studying DNA…Some kinds of DNA wrap themselves into knot formations that can be insanely difficult to decipher. But Mazur says Thurston’s classification [referring to related work] may provide a way to calculate the exact nature of any knot – so in theory it could be used to work out the structure of knotty DNA molecules.

The upper reaches of mathematics can often seem absurdly detached from life down here on planet earth, but Mazur points out that you can never know where things might lead. He cites the case of James Clerk Maxwell. In the late 19th century Maxwell worked out the equations of electromagnetism. “At the time it would have been easy to write off Maxwell’s ideas about invisible forces as a mystical abstraction,” Mazur says. But Maxwell’s work laid the foundations for the development of radio, and hence the communications revolution. Every time we turn on the TV or pick up a cellphone or log onto a WiFi system we are reaping the rewards of Maxwell’s equations.

Another bottom line: Perelman will receive a million dollars if his result stands up. Alex says this is another win for bounty hunters!

Social psychologists have found that women prefer to have sex with a “Cad” when considering a brief affair but for longer term relationships they prefer “Dads.” Leading Tyler to ask in an earlier post, Why do women like cads?

Patrick Vlaskovits, a reader, hypothesizes that Cads have better genes than Dads. Patrick writes:

Why is a Cad a Cad? I think it is because: He can be. His genes are so good, so much in demand, that women are willing to mate with him knowing that he might not stick around. Same reason why a Dad is a Dad. He knows if based solely on looks (proxy for gene competition), he will lose to the Cad every time. So, he must compensate for his lower quality genes by investing more resources in the female and offspring.

Symmetry is an important aspect of beauty and has been shown to be a signal of good genes so the theory can be tested by looking at how mating strategies vary with symmetrical features. Psychologists Steven Gangestad and Jeffrey Simpson report that this has been done with birds:

In a recent review of 18 bird species, Møller and Thornhill (1997a) have documented an association between extra-pair paternity and the extent to which attractive males engage in direct parental care. Specifically, when the rate of extra-pair paternity is high (and, thus, when males can benefit more from trying to attract extra-pair mates), attractive males perform a smaller proportion of offspring feedings than do less attractive males. Exerting greater extra-pair mating effort should yield larger payoffs for more attractive males, and this is evident in the time they fail to spend engaging in a competing activity: providing direct parental care.

Gangestad and Simpson suggest that the theory also applies to humans:

Over evolutionary history, men who had indicators of genotypic quality should have experienced larger gains in fitness payoffs than men who lacked these indicators. Moreover, men should have evolved to conditionally “decide” to allocate more versus less effort to mating or parenting, depending on the degree to which they possess these features.

Note, however, that the context in which men play the Cad v. Dad strategy, human society, is much more variable than that faced by birds. The Cad strategy will not work well in times and places where extra-marital sex is uncommon. Ever heard of an Amish Cad?