Category: Science

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.

Yup, that”s right. And yes, new ideas do come first to California, at least in this case.

Scientists at the University of California at Berkeley are using ground penetrating radar (GPR), a tool better known for its military uses, to help winemakers create tastier, more uniform wines.

“GPR is an electromagnetic signal that travels in the ground. What we do is try to understand how fast that signal travels and that tells us a lot about the moisture content of the soil,” said Susan Hubbard, a hydrogeophysicist at University of California, Berkeley, and staff scientist at Lawrence Berkeley National Laboratory.

Understanding soil moisture is a critical part of the art and science of winemaking. Cabernet Sauvignon and other red wine grapes prefer drier soil. Chardonnay and other white wine grapes do better in moist soil. But growers say the timing, and the amount of water given to the vines can make the difference between an average and an outstanding crop.

Read here for the full story.

Let’s not forget, the initial French advantage in winemaking was based on technology, albeit of a more informal sort. If the French don’t keep on innovating, they will be left behind.

Athletes will be the first to be genetically engineered. Suspicions have already been raised about the 14 and 15 year old record-breaking track stars from China. He-Man mice have been created in the lab. All this makes me blase about drug doping and the recent banning by the FDA of a previously difficult to detect steroid. Indeed, I look forward to seeing the new superathletes in action. Imagine the possibilities in all fields of human endeavour. The new concertos written for 12 fingered pianists will be glorious.

This knack for calmly sailing through the rigors of parenting is no accident, however. Mothers have cooler heads and better coping skills than nonmothers.
It’s all part of the “maternal brain,” according to Craig Kinsley, a psychologist with the University of Richmond. He has presented his findings in the journal Physiology and Behavior this month.
“Reproduction shapes and alters a female’s brain in significant ways,” he said yesterday.
Essentially, the motherly mind does not tend to dwell on fear or confusion in the face of adversity or challenge.

The experiment was done with rats:

He based the conclusions on four years of research with female rats who had, well, their little paws full. Mr. Kinsley and his research team found that veteran mother rats were less stressed by a series of lab challenges than females who had never faced a litter of needy babies.
The rats were placed in an open space as well as inside clear plastic tubing in bright light – hair-raising environments for a rat, according to Mr. Kinsley. The researchers found that the momma rats methodically and fearlessly explored the unknown territories, looking for a way out.
The nonmothers froze up or moved with great caution.
In the aftermath, the mother rat’s brains showed less activation of the amydaglia, an area that regulates fear.
“Pregnancy and offspring create a more adaptive brain, one that’s generally less susceptible to fear and stress,” Mr. Kinsley said.

Nor does the effect seem to vanish:

“But what’s most intriguing is that this seems to be a long-lasting effect which persists throughout life,” he added. “It is not temporary.”

Here is Kinsley’s home page. Here is his claim that pregnancy makes women smarter, in addition to calmer.

My take: I can cite one data point, my mother, in favor of the hypothesis.

Tired of sitting at endless red lights? Frustrated by lights that turn from green to red too quickly, trapping you in traffic?

Now anyone can breeze through congested intersections just like the police, thanks to a $300 dashboard device that changes traffic lights from red to green, making nasty commutes a thing of the past and leaving other drivers open-mouthed at your ability to manipulate traffic.

But what if everyone had one?

Fire engines, of course, have been using these devices for some time now, but they appear to be spreading more generally. Here is the full story, courtesy of www.geekpress.com.

The bottom line: “The potential for chaos is enormous,” Macomb County Sheriff Mark Hackel said.

Dealers have promised to sell only to police and the proper authorities, but there appear to be no laws against the devices.

The most dangerous month for accidents is August, which is twenty percent riskier than the average month, presumably because people spend more time outdoors then and more time vacationing. You are most likely to drown in July, most likely to be shot in November, and most likely to fall to your death in December. Could that latter figure be driven by Christmas-time depressives committing suicide?

From The World’s Most Dangerous Places.

“About 60 percent of the women said they would prefer to have sex with a cad when considering a brief affair,” said Daniel Kruger, a social psychologist at the U-M Institute for Social Research (ISR), the world’s largest academic social science survey and research organization.

…the findings imply that the dad versus cad distinction is intuitive to women and remains a key element of contemporary mating strategies. Women’s preference for cads for short-term relationships supports what evolutionary psychologists call the “sexy son hypothesis,” Kruger said. Even though cads aren’t good bets to stick around and help raise children, the genes that make men successful cads will be passed along to their sons, who will increase their mothers’ eventual reproductive success by providing numerous grandchildren.

That being said, few women want their daughter to marry a cad:

…the distinction between dads and cads is intuitive enough that women showed a strong preference for dads [the contrasting male category, defined as caring, nurturing types] as potential sons-in-law. Only 13 percent of the women said they would prefer to see an imagined 25-year-old daughter engaged to a cad. “A cad would be less likely to provide paternal support for offspring,” Kruger said, “which means that a daughter might turn to the maternal family for help. That could adversely impact the grandmother’s overall reproductive success.”

Here is Kruger’s home page. Here is a link to the journal Human Nature, which lists the article as forthcoming. Here is the home page of co-author Maryanne Fisher.

My take: I can’t get my hands on the original paper. But the explanation, as offered, leaves a gap. It shows that a “cads equilibrium” is stable, once in place. But why are the sons of cads, themselves cads presumably, seen as sexy? One woman may want a cad, if she knows that other women will (later) want her son. But where does the female preference for cads, viewed more generally, come from?