In two longitudinal studies, university students, their roommates, and parents assessed the quality and forecast the longevity of the students’ dating relationships. […] Students assessed their relationships more positively, focusing primarily on the strengths of their relationships, and made more optimistic predictions than did parents and roommates. Although students were more confident in their predictions, their explicit forecasts tended to be less accurate than those of the two observer groups. Students, however, possessed information that could have yielded more accurate forecasts. [SAGE]
The systematic biases seen in people’s probability judgments are typically taken as evidence that people do not use the rules of probability theory when reasoning about probability but instead use heuristics, which sometimes yield reasonable judgments and sometimes yield systematic biases. This view has had a major impact in economics, law, medicine, and other fields; indeed, the idea that people cannot reason with probabilities has become a truism. We present a simple alternative to this view, where people reason about probability according to probability theory but are subject to random variation or noise in the reasoning process. […] Results suggest that people’s probability judgments embody the rules of probability theory and that biases in those judgments are due to the effects of random noise. [APA/PsycNET]
Although many studies have reported that women’s preferences for masculine physical characteristics in men change systematically during the menstrual cycle, the hormonal mechanisms underpinning these changes are currently poorly understood. Previous studies investigating the relationships between measured hormone levels and women’s masculinity preferences tested only judgments of men’s facial attractiveness. Results of these studies suggested that preferences for masculine characteristics in men’s faces were related to either women’s estradiol or testosterone levels. To investigate the hormonal correlates of within-woman variation in masculinity preferences further, here we measured 62 women’s salivary estradiol, progesterone, and testosterone levels and their preferences for masculine characteristics in men’s voices in five weekly test sessions. Multilevel modeling of these data showed that changes in salivary estradiol were the best predictor of changes in women’s preferences for vocal masculinity. These results complement other recent research implicating estradiol in women’s mate preferences, attention to courtship signals, sexual motivation, and sexual strategies, and are the first to link women’s voice preferences directly to measured hormone levels. [Hormones and Behavior]
Why do fingers get wrinkly in the water? […] A hypothesis has been proposed which suggests that the wrinkling might be an evolutionary adaptation to make the handling of objects underwater easier. Wrinkling creates a kind of drainage path for water and so enhances the grip on an object (this is called a ‘rain tread’ hypothesis). In order to test if this hypothesis is true Kareklas et al. have recruited volunteers and tested their ability to transfer wet objects when the fingers are wrinkled and not. […] 20 participants had to transfer glass marbles from one container to another in two different conditions (1) take the marble from a container with water pass it through a small hole and put into an empty container and (2) take the marble from a container without water pass it through a small hole and put into an empty container. […] When the marble ball was dry there was no difference between the transfer time with wrinkly and smooth fingers. However, when the marble was wet then on average it took 12% less time to transfer the object with wrinkly fingers. Therefore, the study concluded that the wrinkling of fingers improves the handling of wet objects (which supports the rain tread hypothesis). Why are our fingers not always wrinkled then? In paper’s discussion Kareklas et al. suggest that there potentially are some fitness trade-offs to the wrinkly fingers. Maybe wrinkled fingers are less sensitive to pain, pressure, heat etc. and are therefore damaged easier, which would explain why it is not good to always have those wrinkles. [The Question Gene]
The work done in this room lies at the heart of a department that handles some of the UK’s most cutting-edge research on forensics and anatomy. […] The hand is Meadows’ area of focus. Variations in scars, skin pigmentation, the smallest nooks and crannies of the fingernail and, most importantly, superficial vein patterns: all of these can build a body of evidence and allow the police to identify an offender in an incriminating photograph. “The back of the hand is part of the anatomy that an offender is quite happy to have in an image, whereas they wouldn’t necessarily want their face captured,” Meadows says. In 2009, Cahid’s work was instrumental in the Neil Strachan case, part of Scotland’s biggest paedophile ring. His unusually distorted lunula (the white half moon at the bottom of a nail) helped identify and convict him. Meadows and her colleagues have built up the UK’s only database of the hand’s vein patterns, with around 800 samples. Of the 40 or so cases they have worked on, their data have resulted in over 80 per cent of suspects changing their plea. [FT]
Dartmouth researchers demonstrate in a new study that a previously understudied part of the brain, the retrosplenial cortex, is essential for forming the basis for contextual memories, which help you to recall events ranging from global disasters to where you parked your car.
Regular exercise may alter how a person experiences pain, according to a new study. The longer we continue to work out, the new findings suggest, the greater our tolerance for discomfort can grow. [NY Times]
Three Perimeter Institute researchers have a new idea about what might have come before the big bang. What we perceive as the big bang, they argue, could be the three-dimensional “mirage” of a collapsing star in a universe profoundly different than our own.
[They] analyzed a database of 6,500 restaurant menus describing 650,000 dishes from across the U.S. Among their findings: fancy restaurants, not surprisingly, use fancier—and longer—words than cheaper restaurants do (think accompaniments and decaffeinated coffee, not sides and decaf). Jurafsky writes that “every increase of one letter in the average length of words describing a dish is associated with an increase of 69 cents in the price of that dish.” [...] Cheaper establishments also use terms like ripe and fresh, which Jurafsky calls “status anxiety” words. Thomas Keller’s Per Se, after all, would never use fresh—that much is taken for granted—but Subway would. [The Atlantic]
Peter Drucker once observed that, “Much of what we call management consists of making it difficult for people to work.” […] Bain & Company studied a sample of big firms, finding that their managers spent 15% of their time in meetings, a share that has risen every year since 2008. Many of these meetings have no clear purpose. The higher up you go, the worse it is. Senior executives spend two full days a week in meetings with three or more colleagues. [The Economist]
Managers of Walgreen’s drugstores in the US “often retire in their 40s.” […] In India, hair dressers can earn more than employees in the software industry.
Honda is one of the few multinational companies that has succeeded at globalization. They’ve never lost money. They’ve been profitable every year. And they’ve been around since 1949, 1950.
Two Stanford researchers have discovered that a species of harvester ants determine how many foragers to send out of the nest in much the same way that Internet protocols discover how much bandwidth is available for the transfer of data. The researchers are calling it the “anternet.” [Thanks Tim]