The low road can be seen as "wet," dripping with emotion, and the high road as relatively "dry," coolly rational. The low road traffics in raw feelings, the high in a considered understanding of what's going on. The low road lets us immediately feel with someone else; the high road can think about what we feel. Ordinarily they mesh seamlessly. Our social lives are governed by the interplay of these two modes [see Appendix A for details].
An emotion can pass from person to person silently, without anyone consciously noticing, because the circuitry for this contagion lies in the low road. To oversimplify, the low road uses neural circuitry that runs through the amygdala and similar automatic nodes, while the high road sends inputs to the prefrontal cortex, the brain's executive center, which contains our capacity for intentionality–we can think about what's happening to us.
The two roads register information at very different speeds. The low road is faster than it is accurate; the high road, while slower, can help us arrive at a more accurate view of what's going on. The low road is quick and dirty, the high slow but mindful. In the words of the twentieth-century philosopher John Dewey, one operates "slam-bang, act-first and think-afterwards," while the other is more "wary and observant."
The speed differential between these two systems–the instant emotional one is several times faster in brain time than the more rational one–allows us to make snap decisions that we might later regret or need to justify. By the time the low road has reacted, sometimes all the high road can do is make the best of things. As the science fiction writer Robert Heinlein wryly noted, "Man is not a rational animal, but a rationalizing one."
While visiting a certain region of the country, I remember being pleasantly surprised by the friendly tones of the taped voice on the telephone that informed me, "Your call cannot be completed as dialed."
The warmth in that bland recorded message, believe it or not, gave me a small trill of good feeling–due largely to my years of irritation with that same message as delivered by my own regional phone company's computerized voice back home. For some reason, the technicians who programmed that message had decided that a grating, hectoring tone hit the right note, perhaps as an immediate punishment for misdialing.
I had grown to resent the obnoxious tones of that taped message–it brought to my mind the image of a too-prissy, judgmental busybody. Without fail, it put me in a bad mood, if just for a moment.
The emotional power of such subtle cues can be surprising. Consider a clever experiment done with student volunteers at the University of Würzburg in Germany. Students listened to a taped voice reading the driest of intellectual material, a German translation of the British philosopher David Hume's Philosophical Essay Concerning Human Understanding. The tape came in two versions, either happy or sad, but so subtly inflected that people were unaware of the difference unless they explicitly listened for it.
As muted as the feeling tones were, students came away from the tape either slightly happier or slightly more somber than they had been before listening to it. Yet the students had no idea that their mood had shifted, let alone why.