Humans

Popular tormentors
Moderately popular teens, not social outcasts or the most popular kids, frequently harass their peers physically, verbally and by spreading gossip, say University of California, Davis, sociologists Robert Faris and Diane Felmlee. Kids at the very top of the social totem pole at middle schools and high schools in North Carolina rarely picked on other students over a three-year span, the researchers report in the February American Sociological Review. But teens in the middle of the popularity pack regularly used harassment to maintain and advance their social standing. Bullying prevention programs should address the types of harassment practiced by moderately popular kids, in their view. —Bruce Bower

Pointing to connect
Kids start to point with their index fingers at around age 1 as a way to look at things together with a caretaker, according to a study led by psychologist Ulf Liszkowski of the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands. One-year-olds who finger-pointed — 19 of 39 studied — did so more frequently than their mothers when exploring a room stocked with toys and other goodies. Infants used finger pointing to draw moms into interactions about what they both saw, Liszkowski suggests online February 1 in Cognitive Development. —Bruce Bower

Zap of insight
Solving a familiar problem in a new way often requires a sudden burst of insight. Only 20 percent of research volunteers could solve a puzzle that required a completely new approach, but by stimulating and repressing certain parts of subjects’ brains, Australian researchers tripled that number. Electrodes boosted activity in the right side of a region called the anterior temporal lobe, which might be heightening people’s creativity. Other electrodes decreased activity in the left side, which might suppress entrenched and ineffective ideas about how to solve the problem. The results, published online February 2 in PLoS ONE, suggest how the brain might discard old ideas in favor of better ones. —Laura Sanders

Tweet if you’re happy
The death of the King of Pop plunged Americans into a trough of despair, according to an analysis of more than 2 billion tweets chirped since September 2008. Aiming to create a “hedonometer,” researchers from the University of Vermont in Burlington assessed the word usage of more than 50 million Twitter users on various time scales. The work, reported online January 26 at arXiv.org, reveals universal patterns such as morning optimism (heavy use of happy, free and less use of bored, hell and hate)and day bias (Tuesdays suck more than Mondays). The day Michael Jackson died was the only substantial system-wide drop in happiness not associated with a well-established cultural, national or religious event. —Rachel Ehrenberg

Picky grandparents
Women who have grandchildren by their daughters provide the most weekly care to those kids, followed by maternal grandfathers, paternal grandmothers and paternal grandfathers, according to a survey of grandparents in 13 European countries. Only maternal grandmothers are absolutely certain of being genetic kin to a grandchild, possibly explaining their greater willingness to participate in raising grandkids, a team led by psychology graduate student Mirkka Danielsbacka of the University of Helsinki reports online January 24 in Evolutionary Psychology. Paternal grandfathers are least certain of having genetic ties to a grandchild and lag behind other grandparents in time devoted to child care. —Bruce Bower