Why do political smear campaigns outpull positive ones? The nastiness makes a bigger impact on your brain.
And that, says Ohio State University psychologist John T. Cacioppo, Ph.D., is due to the brain's "negativity bias": it is built with a greater sensitivity to unpleasant news. The bias is so automatic that Cacioppo can detect it at the earliest stage of cortical information processing.
In his studies, Cacioppo showed volunteers pictures known to amuse positive feelings (such as a Ferrari or a pizza), negative feelings (like a mutilated face or dead cat) or neutral feelings (a plate, a hair dryer). Meanwhile, he recorded event-related brain potentials, or electrical activity of the cortex that reflects the magnitude of information processing taking place.
The brain, Cacioppo says, reacts more strongly to stimuli it deems negative. Thus, our attitudes are more influenced by downbeat news. Our ability to weigh negative input so heavily evolved, he explains, to keep us out of harm's way.