Sunday, December 16, 2007
Monday, December 10, 2007
Interventions at every age from infancy to college can reduce racial gaps in both I.Q. and academic achievement
Whites showed better comprehension of sayings, better ability to recognize similarities and better facility with analogies — when solutions required knowledge of words and concepts that were more likely to be known to whites than to blacks. But when these kinds of reasoning were tested with words and concepts known equally well to blacks and whites, there were no differences. Within each race, prior knowledge predicted learning and reasoning, but between the races it was prior knowledge only that differed. What do we know about the effects of environment?
That environment can markedly influence I.Q. is demonstrated by the so-called Flynn Effect. James Flynn, a philosopher and I.Q. researcher in New Zealand, has established that in the Western world as a whole, I.Q. increased markedly from 1947 to 2002. In the United States alone, it went up by 18 points. Our genes could not have changed enough over such a brief period to account for the shift; it must have been the result of powerful social factors. And if such factors could produce changes over time for the population as a whole, they could also produce big differences between subpopulations at any given time.
In fact, we know that the I.Q. difference between black and white 12-year-olds has dropped to 9.5 points from 15 points in the last 30 years — a period that was more favorable for blacks in many ways than the preceding era. Black progress on the National Assessment of Educational Progress shows equivalent gains. Reading and math improvement has been modest for whites but substantial for blacks. Most important, we know that interventions at every age from infancy to college can reduce racial gaps in both I.Q. and academic achievement, sometimes by substantial amounts in surprisingly little time. This mutability is further evidence that the I.Q. difference has environmental, not genetic, causes. And it should encourage us, as a society, to see that all children receive ample opportunity to develop their minds. « Previous Page Richard E. Nisbett, a professor of psychology at the University of Michigan, is the author of “The Geography of Thought: How Asians and Westerners Think Differently and Why.”
Saturday, December 08, 2007
- Why did the mapmaker name the territory America and then change his mind later?
- How was he able to draw South America so accurately?
- Why did he put a huge ocean west of America years before European explorers discovered the Pacific?
"That's the kind of conundrum, the question, that is still out there," said John Hebert, chief of the geography and map division of the Library of Congress.
The 12 sheets that make up the map, purchased from German Prince Johannes Waldburg-Wolfegg for $10 million in 2003, were mounted on Monday in a huge 6-foot by 9.5-foot (1.85 meter by 2.95 meter) display case machined from a single block of aluminum...
"From the writings of Vespucci you couldn't have prepared the map," Hebert said. "There had to be something cartographic with it."
MISGIVINGS ABOUT AMERICA
Waldseemuller made it clear he was naming the new land after Vespucci, describing how he came up with the name America based on the navigator's first name.
But he soon had misgivings about what he had done. An atlas Waldseemuller produced six years later shows only part of the east coast of the Americas, and refers to it as Terra Incognita -- unknown land.
"America has gone out of his lexicon," Hebert said. "(No) place in the atlas -- in the text or in the maps -- does the name America appear."...
Although the map conceals many mysteries, one thing is clear: it represents a revolutionary shift in the way Europe viewed the world.
"This is ... essentially the beginning or first map of the modern age, and it's one that everything builds on from that point forward," Hebert said. "It becomes a keystone map." (Editing by Eddie Evans) © Reuters2007 All rights reserved
The presence of certain bacteria in the gastrointestinal tract influences behavior and brain function. For example, challenge with live Campylobacter jejuni (C. jejuni), a common food-born pathogen, reduces exploration of open arms of the plus maze, consistent with anxiety-like behavior, and activates brain regions associated with autonomic function, likely via a vagal pathway.
Solar distance and Earth gravity
The existence of liquid water, and to a lesser extent its gaseous and solid forms, on Earth is vital to the existence of life on Earth as we know it. The Earth is located in the habitable zone of the solar system; if it were slightly closer to or further from the Sun (about 5%, or 8 million kilometers or so), the conditions which allow the three forms to be present simultaneously would be far less likely to exist.
Earth's mass allows gravity to hold an atmosphere. Water vapor and carbon dioxide in the atmosphere provide a greenhouse effect which helps maintain a relatively steady surface temperature. If Earth were smaller, a thinner atmosphere would cause temperature extremes preventing the accumulation of water except in polar ice caps (as on Mars).
It has been proposed that life itself may maintain the conditions that have allowed its continued existence. The surface temperature of Earth has been relatively constant through geologic time despite varying levels of incoming solar radiation (insolation), indicating that a dynamic process governs Earth's temperature via a combination of greenhouse gases and surface or atmospheric albedo. This proposal is known as the Gaia hypothesis.
The state of water also depends on a planet's gravity. If a planet is sufficiently massive, the water on it may be solid even at high temperatures, because of the high pressure caused by gravity.