Category: Science

Monkeys and dolphins are capable of recognizing when they do not know the answer to a question. Here is a brief summary of the experiments:

In the first one, trained monkeys sat at a computer joystick and watched the density of colored dots in a square on the screen. When there were many dots, the monkey moved the joystick to the square itself, choosing “dense.” When there were few dots, the monkey put the cursor on an “S,” superimposed on the screen, indicating “sparse.”

Gradually, examiners added more dots to the “sparse” test until the monkey reached a threshold where it could not easily discern whether the panel was “dense” or not. At that point, the monkey chose to put the cursor on a star, indicating uncertainty.

Smith said the two monkeys displayed uncertainty at almost the same threshold as seven humans who also took the test. This result, Smith and his co-authors said, “presents one of the strongest existing matches between human and animal performance in the comparative literature.”

In the second test, a bottlenose dolphin was trained to press a lever when it heard a “low” tone, and another lever when it heard a “high” tone. At first, the dolphin was so enthusiastic that it kicked up swirls of water as it raced to the levers.

But when researchers raised the low tone until it approached the high tone, “he would creep in because he didn’t know what to do,” Smith said. “It was the dolphin equivalent of scratching its head.” The dolphin would then resort to a third lever, indicating uncertainty.

In other words, very intelligent animals are aware of their own cognitive limitations, here is the full story. So far it has not been possible to induce comparable behavior in rats, nor in many political commentators.

The bottom line: Of all kinds of rationality, meta-rationality is perhaps the hardest to come by. It is most rare when more than one person, or questions of status, are involved. For whatever reasons, a kind of false certainty must have yielded evolutionary advantages in earlier times, and perhaps still does today. Those animals would really impress me if they dropped their admissions of uncertainty when a member of the opposite sex was watching.

Read this feature article from Popular Science magazine, or just buy the December issue. My two favorite new products are the following:

1. Binoculars that repeat the last 30 seconds. Instant replay, right there in your hands, and only $600 from bushnell.com.

2. Speakers that know how to listen. The speakers can measure what kind of sound they are producing in a particular room, and adjust their output accordingly to sound even better, they are called Beolab 5. This item costs a steeper $16,000, I will buy them when they start paying bloggers, from Bang-Olufsen.

Alex will be interested to hear about the new “Lifeport Kidney Transporter,” see organ-recovery.com, now FDA-approved, which makes it easier to move kidneys around the world, the device makes a soon-to-be transplanted kidney last for 17 more hours than previous technologies.

People with implicit racial prejudices are left mentally exhausted after interacting with someone from a different race, perhaps because they are trying to quell their feelings.

The new study, the first of its kind, shows that areas in the brain associated with self-control light up in white people with implicit racial biases when they are shown images of black people.

Furthermore, the study showed that the level of this brain activity correlated very closely with poor performance in a test of thinking ability given right after a face-to-face interview with a black person. The researchers believe this indicates that the subject’s mental resources have been temporarily drained by their efforts to suppress their prejudices.

Here is the full story.

At least in the world of baboons:

Baby baboons born to outgoing mums who enjoy hanging out with other females are considerably more likely to survive their crucial first year than infants born to less friendly mothers…

And the difference is a big one:

Susan Alberts, at Duke University in North Carolina, and one of the research team was surprised by the significance of sociability. “Eight per cent of infant survival is explained by sociality,” she told New Scientist. That is “striking”, she explains, because “we wouldn’t expect to have a large amount of variation that is deterministic – things that a mother can actually control – it’s amazing.”

Here is the full story. In my family of primates, the wife/mother is definitely the sociable one, at night I like to stay at home and write my blog or read.

Here are twenty five questions from the NYTimes ranging from What is Gravity, Really? to Are Men Necessary? Each question comes with a brief explanation and some discussion.

When you first fall in love, you are not experiencing an emotion, but a motivation or drive, new brain scanning studies have shown.

The early stages of a romantic relationship spark activity in dopamine-rich brain regions associated with motivation and reward. The more intense the relationship is, the greater the activity.

Here is the best part, or I suppose I should say the worst part:

Early on in a relationship, the images showed that the brain seems to be very focused on planning and pursuit of pleasurable reward, says Fisher, mediated by regions called the right caudate nucleus and right ventral tegmentum. The same regions become active when a person enjoys the pleasure of eating chocolate, she adds…There are also patterns that resemble aspects of obsessive compulsive disorder.

Here is the story from New Scientist, here is related research on the links between love and OCD. The research also suggests gender differences; male love has more to do with lust than does female love.

This will make setting up a hotel on the Moon much more difficult. I am bummed.

The divorce rate is almost perfectly predictable from the proportion of men to women in the population. In 1920, when the annual divorce rate was eight per one thousand married women, there were 104 males for every female. By 1980 the tables had turned, and there were only ninety-five males for every one hundred females, and the divorce rate had risen to twenty-three per one thousand married women. The sex ratio has remained virtually unchanged for the past thirty years and is paralleled by a steadily high divorce rate. The correlation betwee the population sex ratio (or number of males per one hundred females) and the divorce rate at four-year intervals between 1896 and 1992 was -.91, indicating that changes in the number of men relative to women accounts for 83 percent of the changes in divorce rate.

From Nigel Barber’s The Science of Romance who, on this claim, cites his own Why Parents Matter.

Can this be true? If it is such a neat fact, why have I never heard it before?

A good bit of web searching yielded surprisingly little enlightenment. One Amazon reviewer writes:

On page 150, Barber refers to a 1983 book purporting that the increasing divorce rate was due to a shortage of marriagable men. That was true in 1983. Barber fails to note that by 1987 the marriageable male/female ratio reversed, and we’re now in a “women shortage” era.

Point well taken, we should consider the sex ratio of marriageable people, not the overall sex ratio. More significantly, the general rate of American divorce is rising over time. The sex ratio has been moving in favor of more women as well, at least until recently, perhaps because survival out of childhood depends less on parental discretionary investments, noting that many parents prefer boys to girls. So the correlation may be spurious, rather than representing causality.

The fact is intriguing, but so far it is not a good monocausal theory of the divorce rate.

Regarding this week’s man vs machine chess match. Tyler writes:

I was surprised to see Kasparov favored. Once he lost to Deep Blue, the last big match (Kramnik vs. Deep Fritz) was a draw. I know it is not as simple as Moore’s Law, but hey, don’t these machines improve their game more rapidly than the human players do?

Indeed, they do. Deep Blue was a very expensive, very fast computer specialized for chess and capable of examining some 200 million positions per second. Fritz is no slouch but it is being run on a more or less ordinary four processor Xeon computer capable of analyzing 3 million moves a second. Fritz is thus about 70 times less powerful than Deep Blue. Yet because of improvements in algorithms, Fritz is almost certainly the better player. So the computer players have improved tremendously over the past 6 years – so much so that the computer side is no longer bothering to field its best against the weak humans!

Addendum: Here’s a graph, from Jeff Sonas, of the top computer player ratings versus the top human player. Although, it is true, as Sonas argues, that the best programs do not beat the very best human players but only draw consistently it may simply be inherent in chess that it is impossible or near impossible to beat someone who is playing at the very highest level (similarly it’s impossible for even a mediocre human player to lose in tic-tac-toe.) We should not conclude from this that the computers aren’t improving. Thanks to Nathan Stocker for the link.

Here is an entire web site devoted to skepticism about the greenhouse effect, and whether the burning of fossil fuels is at fault. It offers the latest scientific research on the skeptical side, excellent visuals, and regular updates. I am an agnostic on this issue, and underinformed most of all, but I do feel that this alternative point of view deserves a better hearing.

Here’s the scoop:

In an analysis of more than 1 million fatal crashes in 48 states, Daniel Eisenberg, a post-doctoral researcher at UC Berkeley’s School of Public Health, was surprised to find that the more it rained or snowed in a month, the fewer deadly traffic accidents there were. Specifically, in any given month, an additional 10 centimeters of rain is linked with a 3.7 percent decrease in the fatal crash rate.

“I had expected to see a positive relationship between the amount of precipitation and the rate of fatal traffic accidents, but my analysis revealed a more complex connection between the two,” said Eisenberg.

He also discovered that the risk of an accident on a rainy day increases with the length of the dry spell preceding it. If there has been rain or snow day after day, the danger due to wet conditions falls.

In other words, if you are used to dangerous roads in recent times, you will drive more carefully. But we are weak, feeble creatures who forget about past dangers all too quickly. Click here for the full story.

The researcher suggests an additional explanation for the phenomenon:

“Oil and debris accumulate on the road when it hasn’t rained for a while, making the roads slicker when it first starts to rain,”

Eisenberg finds another interesting result:

…overall, precipitation had a larger impact on nonfatal traffic accidents.

“For any given day in the state, on average, each centimeter of precipitation increases the risk of fatal crashes by about 1 percent, but for nonfatal crashes, the increased risk is 11 percent,” said Eisenberg.

So, on any given day, rain or snow will lead to increases in nonfatal injury crashes and fender benders much more so than to increases in accidents that involve death.

“People who slow down when the weather is bad may not slow down enough to avoid all crashes, but, on average, they at least reduce the severity of the collision,” said Eisenberg.

In other words, to kill yourself being drunk, very stupid, very unlucky, or a very bad driver are the critical ingredients, not the rain.