In a series of experiments, researchers from the University of Nebraska-Lincoln closely monitored physiological reactions and eye movements of study participants when shown combinations of both pleasant and unpleasant images. Conservatives reacted more strongly to, fixated more quickly on, and looked longer at the unpleasant images; liberals had stronger reactions to and looked longer at the pleasant images compared with conservatives.

“It’s been said that conservatives and liberals don’t see things in the same way,” said Mike Dodd, UNL assistant professor of psychology and the study’s lead author. “These findings make that clear – quite literally.”

To gauge participants’ physiological responses, they were shown a series of images on a screen. Electrodes measured subtle skin conductance changes, which indicated an emotional response. The cognitive data, meanwhile, was gathered by outfitting participants with eyetracking equipment that captured even the most subtle of eye movements while combinations of unpleasant and pleasant photos appeared on the screen.

While liberals’ gazes tended to fall upon the pleasant images, such as a beach ball or a bunny rabbit, conservatives clearly focused on the negative images – of an open wound, a crashed car or a dirty toilet, for example.

Consistent with the idea that conservatives seem to respond more to negative stimuli while liberals respond more to positive stimuli, conservatives also exhibited a stronger physiological response to images of Democratic politicians – presumed to be a negative to them – than they did on pictures of well-known Republicans. Liberals, on the other hand, had a stronger physiological response to the Democrats – presumed to be a positive stimulus to them – than they did to images of the Republicans.

By studying both physiological and cognitive aspects, the researchers established unique new insights into the growing notion that political leanings are at least partial products of our biology, UNL political scientist and study co-author Kevin Smith said.

Recent research on the subject has focused mostly on physiological reactions to negative stimuli. The new study’s use of cognitive data regarding both positive and negative imagery adds to the understanding of how liberals and conservatives see and experience the world, Smith said.

UNL political scientist and co-author John Hibbing said the results might mean that those on the right are more attuned and attentive to aversive elements in life and are more naturally inclined to confront them. From an evolutionary standpoint, that makes sense, he said.

The results also are consistent with conservatives’ support of policies to protect society from perceived external threats (support for increased defense spending or opposition to immigration) and internal ones as well (support for traditional values and being tough on crime), Hibbing said.

The researchers were careful to not make a value judgment on either political orientation. But they did note that their discovery provided an opportunity to recognize the relevance of deeper biological variables in politics and turn down political polarization.

Rather than believing those with opposite political views are uninformed or willfully obtuse, the authors said, political tolerance could be enhanced if it was widely understood that political differences are based in part on our physiological and cognitive differences.

“When conservatives say that liberals are out of it and just don’t get it, from this standpoint, that’s true,” Hibbing said. “And when liberals say ‘What are (conservatives) so frightened of? Is the world really that dangerous?’ Given what each side sees, what they pay attention to, what they physiologically experience – the answer is both sides are right.”