SCOTTSDALE - It's the argument of the century: Trump or Clinton. We've all been in the middle of it, but have you ever wondered why so many of these arguments seem to become irrational? There may be a scientific reason behind it.

“About 95 percent of decisions are made at the emotional level,” said Dr. Ron Bonnstetter.

Bonnstetter’s background is in cognitive neurology, and now he focuses on why people do what they do to better match them for jobs.

He’s got a different focus at TTI Success Insights in Scottsdale this political season, though.

“We really are justifying our decisions and when people say they've really looked at the issues, I would want to quiz them a little bit,” Bonnstetter said.

One of his test subjects is Todd Fox, a registered Republican who plans to vote for Donald Trump.

"I really think he's a strong leader, and trust him more than the Democrat,” Fox says.

But Bonstetter hasn’t heard Fox. He believes he can figure out someone’s political leanings through a brain scan.

Pictures flash on the monitor for a second and a half -- just long enough for Fox’s brain to react -- before another pops up. Electrodes then send Todd's brain activity to a computer where researchers can tell whether he reacts in a negative or positive way.

The tell-tale sign here is what happens when a picture of Hillary Clinton comes on the monitor.

"There is a definitely a neutral response followed by a right hemisphere flare. This is a rejection,” Bonnstetter said.

If it was a stimulus he agreed with, the flare would have come up on the left side of the brain.

"I know how I feel so nothing surprised me,” said Fox. “It's just incredible the technology we are able to utilize and draw the information."

The research shows that Democrats generally have a stronger reaction to things they dislike, where as a Republican's brain waves trigger a stronger response to things they do like.

It appears these presidential arguments around the country may involve more science than political science.