- Study: Emotion rules the brain's decisions

The evidence has been piling up throughout history, and now neuroscientists have proved it's true: The brain's wiring emphatically relies on emotion over intellect in decision-making.

A brain-imaging study reported in the current Science examines 'framing,' a hot topic among psychologists, economists and political hucksters.

Framing studies have shown that how a question is posed — think negative ads, for instance — skews decision-making. But no one showed exactly how this effect worked in the human brain until the brain-imaging study led by Benedetto De Martino of University College London.

De Martino and colleagues asked 20 men and women to undergo three 17-minute brain scans while being asked to gamble — or not — with an initial pot of English pounds worth about $95. When told they would 'keep' 40% of their money if they didn't gamble, the volunteers chose to gamble only 43% of the time. Told they could 'lose' 60% of the money if they didn't gamble, they rolled the dice 62% of the time.

Their chances of winning the money were carefully explained beforehand, and participants knew the odds were identical. But the framing effect still skewed their decisions significantly.