I recommend Ian Deary’s Intelligence: A Very Short Introduction. I am going to buy more books in this Oxford series. We at Marginal Revolution aim to provide value for attention, however, so here is an even shorter introduction.
1) Almost all measures of intelligence correlate with one another and quite a few measures of different aspects of intelligence are highly correlated. It is thus meaningful to talk about general intelligence, g. Howard Gardner’s work on “multiple intelligences” is on the fringes of scientific psychology.
2) Intelligence rankings are stable with age but fluid intelligence, meaning something like pure reasoning power, as opposed to crystalized intelligence peaks in the 20-30s and then declines with age.
3) Connecting IQ scores to brain morphology and activity is still in its infancy but there are modest, but well established, correlations between brain size and IQ (psychometric intelligence) and measures of reaction time (which plausibly measure brain speed) and IQ.
4) Intelligence is in large part genetic and that which is due to environment is primarily not due to the obvious possibilities such as family upbringing.
5) Intelligence matters for work performance and education. IQ is a better forecaster of work performance than just about any other test short of a trial run on the actual work to be performed.
6) IQ has been rising, the Flynn effect. No one knows why.
7) None of the above points are controversial among intelligence researchers.
Aside from Dreary’s book another useful introduction to intelligence research is the authoritative consensus report from the American Psychological Assocation, Intelligence: Knowns and Unknowns, summary here.
Mice, taken collectively, are not very good at escaping from a crowded room. They act pretty much as humans do, namely they all crowd toward the door and few get out very quickly. Each individual mouse appears to make a rational calculation of a sort. The mice do best, and adopt some form of queuing behavior, when the door is large enough to let only one mouse through at a time. Researchers suggest that humans may exit a crowded more quickly, the smaller the door, which limits the crush toward the exit. For more information read this article from New Scientist.
A nice article in the Sept. 2002 Social Psychology Quarterly documents an interesting fact: the presidential candidate who has the right tone of voice tends to win the election.
According to “communication accommodation theory,” low status people change their voices to accommodate high status people. The presidential candidate who more frequently changes the “F_0” range of his voice (which is a very low hum) during a debate signals that he is in the low-status position. The authors believe that voters respond strongly to this non-verbal, but strongly emotional, cue. The authors note that George W. Bush may have “won” the 2000 debate with Gore because he signaled his dominance in this fashion, although Gore was perceived by journalists to have won through superior rhetoric. The results of voice analysis correlate well with electoral outcomes and polls.
Sleep research is great fun. Sleep is tied to so much in our lives, yet we know so little and there are always surprises. Consider the latest finding: the position you sleep in is highly correlated to your social personality. Being a log-sleeper (on the side, hugging the pillow) correlates with being outgoing and social, while fetal position sleepers are shy. Sleeping position is not the only correlate of personality. Your handwriting, your job satisfaction and a whole bunch of other things tend to be linked to personality.
The Swede Carl Linnaeus, a father of modern taxonomy, “spent much of his leisure time penning long and flattering portraits of himself, declaring that there had never “been a greater botanist or zoologist…””
Today the world has about 10,000 active taxonomists. It takes eight to ten years to train a good taxonomist. It is commonly believed that the world has a severe shortage of taxonomists, although economists might challenge the use of the word “shortage” in this context.
Logging a new species costs about $2000 per species.
Each year about fifteen thousand new species are recorded. Insects alone offer possibly as many as 100 million undiscovered species.
As of 2002, there were no full-time taxonomists in Africa.
I don’t think it follows, as scientist Koen Maes suggests, that “It’s not a biodiversity crisis, it’s a taxonomist crisis!” Still, we know less about species and their numbers than I had thought.
All this is taken from Bill Bryson’s recent and entertaining A Short History of Nearly Everything, chapter 23. Thanks to Yesim Yilmaz for the pointer.
Very useful tips from Cronaca.com. It is cheaper than you think.
Monkeys appear to have an innate sense of when they are being treated unfairly, read here. Capuchin monkeys will refuse beneficial exchanges, if they see another monkey getting a better deal. Sound familiar? Similar results are found in the literature on experimental economics for humans, as Robert Frank notes at the link.
Here is one summary from The Washington Times, the only paper I can find in today’s Virginia power blackout, they don’t yet have the link on-line:
When both monkeys were given a cucumber slice after handing over the token, they completed the trade 95 percent of the time.
But when one was given the tastier grape for the same amount of work, the rate of cooperation from the other monkey fell to 60 percent…The refusal to make the exchange increased as the experiment continued…The scientists concluded that capuchins apparently measure rewards in relative terms…the tropical forest-dwelling capuchins were chosen for the experiment because they often share food.
One commentator on the study, a Charles Janson of SUNY, suggests that the behavior of the monkeys might have been learned in captivity (again, cited in The Washington Times).
Could ghost sightings be declining with the advent of cell phones? Will haunted houses lose their luster? The link is from the ever-excellent www.cronaca.com.
I can think of at least two explanations for this possible phenomenon. First, perhaps people with cell phones feel safer and hallucinate less. Second, perhaps it is harder to lie/self-delude right on the spot than afterwards, imagine telling your friend there is a ghost right next to you now. What if your friend asks to speak to it or hear it groaning? I also would like more data, how about alien abduction stories, noting that spaceships are presumably “dead zones.” My calling plan does not mention them…
People will often abandon their opinions to conform to what a group expects of them, but a lone voice of reason can save the day. Cass Sunstein’s new book, Why Societies Need Dissent, reports the following (see chapter one):
You can give people a problem and allow them to solve it. Also give them a group of confederates, who unanimously advocate the wrong answer to the same problem. One confederate, proclaiming the wrong answer, will have little influence on the problem solver. Two confederates increased errors to 13.6 percent. Using three confederates increased errors to 31.8 percent. Under some results, more than three confederates do not increase the error rate, although this is controversial. But putting one voice of sanity in the group, who knows and proclaims the right answer, makes a big difference. “Conformity errors” were reduced by an average of three quarters, even if a strong majority of the group leaned the other way. Sunstein draws upon the work of Robert Baron, at the University of Iowa.
The Australian BBC reports: “Medieval recipes for gunpowder produce nearly the same firepower as today’s manufactured equivalent, according to recent weapons tests, providing clues as to how the British fleet became one of the largest fighting forces in the world.” The full account is can be obtained through www.cronaca.com.
According to an article in the 23 Aug. issue of New Scientist magazine (unfortunately not available online to non-subscribers) scientists have been “absolutely shocked” to find that glaciers in the south pole have been “eroding at a rate of 3 meters per year or more.” According to one scientist “all the visible ice, all the carbon dioxide that we see in the ‘permanent’ ice cap could be eroded in less than a century.”
The scientists agree that the only plausible explanation of what they are seeing is “climate change” but none of them think that humans are to blame. Why not? The scientists are talking about Mars. The article doesn’t make the connection but it seems to me that global warming on Mars raises the plausibility of claims by global warming skeptics that solar activity could be responsible for much climate change on Earth. Here is a picture from Friis-Christensen and Lassen’s 1991 paper on this issue in Science (link to JSTOR, click on the picture to expand).
Fungi under the snow may contribute significantly to CO2 levels, according to this Washington Post article (brief registration required). Here is one bit:
“We’re living in a world where global warming is a constant threat, but in fact we have relatively little knowledge of what the inputs and outputs are for CO2.” said Steven Miller, a mycologist, or fungus specialist, at the University of Wyoming.”
Here is another:
“…global warming models can no longer ignore fungi in snowy regions and seasons as they have, scientists said – especially because about 40 percent of Earth’s landmass is covered with snow for at least part of the year.”
I am not one of those economists who wishes that global warming would go away, and simply assumes that science is on my side, or reads the evidence selectively. And of course items such as this can be cause for either optimism or pessimism, what if fungi under the snow contribute to a crisis rather than easing it? Still, Bush was not crazy to refuse to go along with Kyoto.
I saw my first one today – a Segway, ridden by a student! It went by me quite fast. Will they become the next cool item on spread-out suburban campuses? Maybe, but I predict students will still be late for class.
An article in today’s Washington Post cites recent research on the heritability of IQ. Here is the bottom line:
“Genes do explain the vast majority of IQ differences among children in wealthier families…But environmental factors – not genetic deficits – explain IQ differences among poor minorities.” The IQ heritability quotient is 0.72 for well-to-do families, but only 0.10 for poor families. The key data involves 623 pairs of twins born to poor black mothers. It seems that genes and environment interact to a greater degree than had previously been thought, perhaps good genes help you only significantly only when you have a certain minimum level of educational opportunity.
The piece will be out in the November issue of Psychological Science, here is the home page of the author, Eric Turkheimer.