Braking Up Is Easy to Do (In Traffic)
Quick hits from the professoriat: That’s the brakes for those caught in traffic, it’s a grand old (subliminal) flag, and Amber Alerts get a yellow light.
All traffic jams are annoying, but particularly frustrating are those that occur for no apparent reason — the ones that make you crawl along for miles, expecting to find a blocked lane. Instead, the traffic simply frees up, and you speed on your way, fuming about lost minutes and wondering what that was all about.
Mathematicians at the University of Exeter have created a model that finally explains what is going on. They discovered that when a driver slows down suddenly — say, in response to a truck unexpectedly pulling into his or her lane — the driver of the car directly behind him hits the brake a tiny bit harder, reducing his speed to ever so slightly less than the first car’s. In turn, the next car slows a bit more than the second, and so on down the line, until a vehicle a mile or two away is forced to come to a complete halt.
Once this domino-like effect starts, there’s no way to stop it, so the only hope lies in the alertness of that first driver. “A slight braking from a driver who has identified a problem earlier will allow the traffic slow to remain smooth,” says mathematician Gábor Orosz. “Heavier braking, usually caused by a driver reacting late to a problem, can affect traffic flow for many miles.” He calls this effect a “backward traveling wave,” a lyric worthy of The Beach Boys, whose songs always did sound good on a car radio.
The effect of subliminal messages can be tricky to predict. A team at Hebrew University of Jerusalem led by cognitive scientist Ran Hassin asked two groups of Israeli citizens about their attitudes toward core issues in the ongoing conflict with the Palestinians. One group was then exposed to images of the Israeli national flag, which flashed by so quickly that the participants were not aware of them.
In the subsequent discussion, participants who were exposed to the flag consistently shifted their opinion, opting for a more moderate, centrist stance. These results were replicated in two follow-up studies, both of which suggested subliminal images of the Israeli flag drew participants to the middle of the political spectrum. Would subliminal exposure to the Stars and Stripes have a similar effect on politically polarized Americans? It’s a question worth running up the flagpole.
The U.S. has the world’s highest mastectomy rate, a fact that has long puzzled public-health experts. Surveys have found nearly one-third of American women diagnosed with early-stage breast cancer insist on a full breast removal, even when their physician recommends a lumpectomy. Why do they opt for more extensive, expensive and painful surgery when long-term survival rates for the two procedures are virtually identical?
Nancy Wong, an assistant professor of marketing at Georgia Tech, interviewed women who made that choice. Many of them found personal anecdotes more persuasive than statistical studies: When Nancy Reagan had a mastectomy, many women followed suit. But Wong also blames what she calls “the pink ribbon culture” — the fight-breast-cancer campaign, which relies heavily on war metaphors in its ads, pamphlets and press releases. Symbolically, “mastectomy signifies a total victory over breast cancer,” she says, “whereas lumpectomy seems to represent something more akin to a truce, which the untrustworthy enemy may not honor.”
Wong and co-author Tracey King argue a new national narrative is needed regarding disease, one that focuses more on the practical management of our aging bodies and less on the problematic notion that aggressive treatment can restore us to perfect health.
The high-profile AMBER Alert system is so inherently flawed it amounts to little more than “crime-control theater,” according to a critical study by researchers at the University of Nevada, Reno. Lead author Timothy Griffin notes the rapid-response system, named after a 9-year-old murdered in Texas, uses everything from freeway signs to text-messaging devices to spread the word that a child has been abducted. It was created to address a horrifying reality: Three-quarters of children who are kidnapped and murdered are killed within three hours of their disappearance.
Griffin’s examination of 275 AMBER Alerts from 2003 to 2006 found that they were issued during those critical three hours only 37 percent of the time; usually it took longer than that for police to verify precisely what had happened. What’s more, 80 percent of the alerts turned out to be false alarms: That is, the child was abducted not by a stranger but by a relative or an acquaintance (usually a divorced or separated parent in a custody dispute) who intended no harm.
Griffin notes that 90 youngsters were kidnapped by a stranger in the U.S. in 1999, out of a total of 262,000 child abductions. “AMBER Alerts, by design, generate an enormous amount of public attention to a category of crime that is extremely rare,” he says. “They enable public officials to make it look like they are solving a problem which, in reality, probably can’t be solved.”
It was proposed by the ancient Greeks, popularized by 19th-century Christian thinkers and dramatized by Disney. So it’s no surprise we pretty much all believe in the “balance of nature.” Small problem: The concept fell out of favor with ecologists two decades ago. We now know nature is in a constant state of flux, and any balance or stability it achieves — say, between predators and prey — is short-lived.
Surveying students at two major Midwestern universities, psychologist Corrine Zimmerman of Illinois State University and ecologist Kim Cuddington of Ohio University found that the discredited idea of natural balance is almost universally accepted. Even science majors who had completed an ecology course were reluctant to let the notion go. “They’re almost unable to reason logically about environmental problems, because they keep bumping into this cultural concept,” Cuddington says.
The authors recommend better training for middle-school and high-school science teachers, who could correct such mistaken thinking early — if they didn’t believe in balance themselves. Zimmerman suspects the erroneous belief is one reason we aren’t more alarmed by the prospect of global climate change: “People think, ‘Everything will be OK. It’ll all balance out in the end.’”
WWho is the underdog in the Israeli-Palestinian conflict? Your answer to that question may determine which side you support, according to researchers at the University of South Florida. Two sets of students were given the same information about the history of the bitter dispute, but the written essay was accompanied by different maps. One was tightly focused on the immediate area in question, showing that Israel is considerably larger than the Palestinian territories. The second presented Israel in the context of the larger Middle East, looking quite small compared to the vast expanses of Jordan, Syria, Saudi Arabia and Egypt.
A majority of participants given the first map were more supportive of the Palestinians, while three-quarters of those given the second map expressed more support for Israel. To the researchers, led by psychologist Joseph Vandello, this represents further evidence that people tend to support the competitor they perceive as the little guy. He suggests this tendency is “rooted in principles of justice, fairness and deservingness” — a comforting idea until you consider how subjective those terms can be. No doubt the maps also reflect the Israelis’ and Palestinians’ self-perceptions as heroic warriors facing larger, more powerful foes.
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