2014 : WHAT SCIENTIFIC IDEA IS READY FOR RETIREMENT?

British Chef Heston Blumenthal's imaginative "Hot and Iced Tea," is a syrupy concoction that's prepared by putting a divider down the middle of a glass, then filling one side with a hot tea and the other with an iced version. Because of the viscous consistency of the liquid, when the divider is removed, the two halves keep separate long enough for a lucky diner to sample a perfectly, and simultaneously, hot and iced tea. When you sip Blumenthal's tea it makes no sense to argue about whether it's really cold or really hot. You could, of course, take care to sip only from the cold side, or only from the hot. But the cup of tea is really both.

I think much of the world, the sciences, certainly the social and behavioral sciences, look more like that cup of tea than we often let on.

We typically assume, for example, that happiness and sadness are polar opposites and, thus, mutually exclusive. But recent research on emotion suggests that positive and negative affects should not be thought of as existing on opposite sides of a continuum, and that, in fact, feelings of happiness and sadness can co-occur. When participants are surveyed immediately after watching certain films, or graduating from college, they are found to feel both profoundly happy and sad. Our emotional experience, it turns out, is a lot like a viscous cup of tea: It can run hot and cold at the same time.

The same can be true of good and evil. Like sipping from the hot or the cold side of the cup, we now know that minor contextual nuance can make all the difference. In one classic study, psychologists Darley and Batson recruited Seminary students to deliver a sermon on the parable of the Good Samaritan. While half the seminarians were told they were comfortably ahead of schedule, others were led to believe they were running late. On their way to give the talk, all participants encountered an ostensibly injured man slumped in a doorway, groaning and needing help. Whereas the majority of those with time to spare stopped to help, a mere 10% of those who were running late stopped, the rest stepping over the victim and rushing along. Notwithstanding their ethical training and biblical scholarship, the minor nuance of a time constraint proved critical to the seminarians' decision to ignore the pleas of a suffering man. Like a high-concept cup of tea, both hot and iced, each of these men were both caring and indifferent, displaying one trait or the other depending on arbitrary twists of fate.

Or consider John Rabe, the bald and bespectacled German engineer, known as "the living Buddha of Nanking." Rabe was the legendary head of the International Safety Zone, who was credited with having saved hundreds of thousands of Chinese lives during a savage Japanese occupation. On the other side of the cup, Rabe was simultaneously the leader of the Nazi party in the same city. In 1938 he assured audiences that he supported the German political system "100 percent."

In its essence, this sort of anti-Manichaean perspective posits that not only one alternative always obtains. If you believe people are only always good, or always only evil, if you think the cup is only ever hot, or only cold, well then you're just wrong - you haven't felt the cup, and you have a terribly naïve understanding of nature. But as long as your views are not that extreme, as long as you recognize the possibility of both cold and hot, then in many cases you needn't choose - it turns out they're both there.

From the little I understand, physicists question the classical distinction between wave and matter, and biologists refuse to choose between nature and nurture. But let me stay close to what I know best. In the social sciences, there is ongoing, and often quite heated, debate about whether or not people are rational, and about whether they're selfish. And there are compelling studies in support of either camp, the hot and the iced. People can be cold, precise, selfish and calculating. Or they can be hot-headed, confused, altruistic, emotional and biased. In fact, they can be a little of both; they can exhibit these conflicting traits at the very same time. People can be perfectly calibrated weather forecasters but hopelessly overconfident investors; ruthless rulers and cuddly pet owners; compassionate friends and apathetic parents. Research on decisions made in demanding contexts has found that people can be thoughtful and calculating as they focus on issues of immediate concern, but negligent and misguided when it comes to issues—sometimes very closely related and equally or more important—just at the periphery of their attention.

As we all know, history is filled with very smart people who did really stupid things, and with good people who acted horribly. Are we altruistic or selfish? Smart or stupid? Good or evil? Like that hot and iced tea, there is always a little of both—it just depends on which side you drink from.