In the movie The Iron Lady, Margaret Thatcher's daughter is worried about her mother's mental state. Mrs. Thatcher is no longer Prime Minister of the U.K. She has lost her husband to death, her son to distance, and her position as head of the government to the opposition. The daughter insists Mrs. Thatcher see the family physician.

The doctor examines her and finds nothing physically wrong. He begins to ask her about her feelings. Mrs. Thatcher stops him in mid-sentence.

"That's the trouble with the country today," she says. "People don't think any more. They care more about feelings than they do about thoughts and ideas."

Perhaps, but it isn't that simple. Often what passes for thought isn't thought at all. It comes from a different part of the brain. Decisions we believe to be rational are often made at a very basic, almost instinctive level. Certain words, certain images, trigger an emotional response, and that response short-cuts rational thinking.

This is nothing new. Ad men, public relations people, political consultants, have always known it. What is new is a spate of popular books on the subject. In "The Political Mind," author George Lakoff, professor of linguistics at the University of California at Berkeley, makes the connection between cognitive science and political campaigns. In "The Political Brain," Drew Westen, professor of psychology at Emory University, explains what happens when emotionally-charged information reaches the brain.

In "Blink," Malcolm Gladwell, a former science writer for the Washington Post, tells us why some people make brilliant decisions while others repeatedly miss the mark. But the most readable book on the subject is "Thinking, Fast and Slow" by Daniel Kahneman, a recent Nobel Prize winner in economics for his work on decision-making.

The brain, Kahneman explains, has two systems that handle the way we process information. One is fast and intuitive; the other is slower and more rational. Neither is superior to the other. They simply evolved differently and serve different purposes.

The instinctive and emotional part of our brains, system No. 1, comes into play when we must make a snap decision, when we're faced with a threat or other situation that requires an immediate response. This is the more primitive part of the brain.

But when we make a business or political decision, something that impacts our long-term welfare, we need to reason before we act. This is when the frontal cortex, the newer part of the brain, goes to work. This is system No. 2. Unfortunately, if the decision involves emotions, or when it impacts a long-held bias or early conditioning, system No. 1 can override system No 2.

One outcome is not necessarily better than another, but understanding how these systems work and how they affect our thinking is important if we want to make rational choices.

Unfortunately, understanding how the mind works can also subvert rational decisions. Ad men know this; politicians know this. Press the right buttons, use the right words, and you can get the response you want.

Back in 1995, Newt Gingrich advised GOPAC, a Republican political training organization, to publish his memo entitled "Language: A Key Mechanism of Control." In it he listed words to use and words to avoid in political messages.

In chapter four of "Thinking Fast and Slow," Kahneman elaborates on this. He makes the connection between an emotional response and a very real physical response to certain words. The chapter is a mere nine pages, and I guarantee it will change the way you look at any political message (I will send a copy of those 9 pages to anyone who asks).

Nobody likes to be manipulated. Nevertheless, we're exposed to it every time we pick up newspaper or turn on the TV. Remember this next time you listen to a campaign speech or political ad. Are they really telling you what you need to know, or are they messing with your head?

Joan King is a Sautee resident whose columns appear biweekly on Tuesdays and at gainesvilletimes.com/viewpoint.