Humans

The sophisticated lives of early North Americans, plus third arms and drunken memories in this week's news

God views tied to HIV course

Religious beliefs cut two ways among HIV-infected people. Faith in a benevolent God predicts relatively slow disease progression over four years, whereas belief in a punishing God heralds immune-system deterioration over that period, say psychologist Gail Ironson of the University of Miami and her colleagues. Positive and negative views of God were linked to rising or falling immune function in 101 HIV patients, after accounting for depression, coping skills and church attendance, Ironson’s team will report in the Journal of Behavioral Medicine. Believers in a merciful God may have numerous close relationships that help to boost physical health, the scientists suggest. —Bruce Bower

Intoxicating memories

Booze doesn’t necessarily abuse eyewitness memories. College students who viewed a staged theft in a lab — some while intoxicated, others while sober — remembered roughly the same number of details about the offense, and proved equally susceptible to believing misinformation about it when interviewed after the incident, say psychologist Nadja Schreiber Compo of Florida International University in Miami and her colleagues. Volunteers generally thought that they had seen an actual theft. Widespread mistrust of crime accounts given by eyewitnesses who qualify as legally intoxicated during the incident may be misplaced, the researchers will propose in Law and Human Behavior. —Bruce Bower

Hit by the heat

Blistering heat steams up an urge to retaliate in Major League baseball pitchers who have seen one or more teammates hit by pitches. An analysis of 57,293 Major League games by psychologist Richard Larrick of Duke University in Durham, N.C., and colleagues showed that the probability of a pitcher hitting a batter progressively increases as temperatures rise and as more of the pitcher’s teammates have been hit by the opposing team’s hurlers earlier in the game. The analysis will appear in Psychological Science. —Bruce Bower

Ancient American Islanders

Early North American settlers made sea crossings to islands off the continent’s west coast by around 12,000 years ago, according to a report in the March 4 Science. Excavations on California’s Channel Islands, directed by anthropologist Jon Erlandson of the University of Oregon in Eugene, have identified prehistoric sites where people used sophisticated stone spear points to capture geese, cormorants and other birds, as well as sea creatures including seals and fish. Stone tools from the Channel Islands look like artifacts from several western North American sites of comparable age, signaling possible long-distance travel and trade.  —Bruce Bower

Getting a third arm

For those who sometimes feel they need a third arm to get through the day, Swedish researchers are here to help. In lab experiments, neuroscientist Arvid Guterstam of the Karolinska Institute in Stockholm and his colleagues gave volunteers the illusion of having three arms. Synchronized brush strokes delivered to each person’s right hand and to an adjacent plastic right hand attached to a rubber arm produced the sensation of having two right arms, the scientists propose online February 23 in PLoS ONE. This research may yield ways to help amputees and paralysis patients exert control over advanced artificial limbs. —Bruce Bower