Should you invest in a risky start-up company? Should you accept that better-paying but less secure job? Should you abandon your failing marriage?
How you answer depends on what kind of brain you have. Researchers at the University of California, Los Angeles, applied functional magnetic resonance imaging to test subjects playing gambling games, and assessed their brain activity. Thinking about the possibility of winning money turns on some of the same areas of the brain as taking cocaine, eating chocolate or looking at a beautiful face. Most people are naturally cautious because their brains are wired to be more sensitive to losses than to gains. But the authors found a wide variation among individuals. "We can predict how risk-averse you are going to be in your choices," says coauthor Russell Poldrack. Marketers take note: the work may eventually lead to ways of predicting purchasing behavior.
Mars was wet and warm 3.5 billion years ago, covered by a thick blanket of carbon dioxide, but now it's dry and cold. The leading explanation has been that the sun's rays blew the atmosphere away like the down of a thistle. Not so, say scientists at the Swedish Institute of Space Physics in a recent report in the journal Science. The carbon should still be there, hidden somewhere in underground reservoirs. Finding it will keep Ph.D.s busy for years.