Don't Know Much Of Biology

Just think about what it takes to learn biology. Not textbook biology, the kind you learn in high school with microscopes and dissecting kits. Rather, the kind you learn on your own, as a young child encountering the vast and diverse world of living things. How does the human mind link together things as varied as hippos and lichen and mosquitoes and rhododendrons? And how do we sort this diversity into meaningful categories? In short, how do we think about life?

Psychologists are very interested in how the mature mind sorts the living world, and where we put ourselves in relation to other life forms. That’s the stuff of philosophy and religion and morality. But it’s not as obvious as one would think. Take motion, for example. Many living things move, but so do rivers and clouds and rocket ships. And some living things, like coral, don’t appear to move at all. So it’s not just the fact of motion that defines life, but the why and how. Young children find this confusing and make a lot of mistakes about what’s animated and what’s not. Only over time do we outgrow our primitive, childish ideas and replace them with a sophisticated view of the natural world.

Or do we? Do we really discard all our naive thinking as we experience the world and learn about its complexity? University of Pennsylvania psychologists Robert Goldberg and Sharon Thompson-Schill have been exploring these questions in the laboratory, with intriguing results. Here’s one of their experiments:

The psychologists showed a group of college students a long list of words, one at a time and very rapidly. Some were the names of plants, others animals, and still others non-living things. The non-living things were further divided into non-moving objects like brooms; non-moving natural things, like boulders; moving artifacts like trucks; and finally, natural moving things, like rivers. The idea was to see how quickly and accurately the volunteers used movement and “naturalness” to classify these various things as living or non-living.

The scientists were particularly interested in how we think about plants, where we put them in the grand scheme of things. Plants are an interesting anomaly because—at least to young children—they don’t “do” anything; instead, we do things to them, like climb them and water them and prune them. If they move at all, their movement is very subtle. Not surprisingly, kids often misclassify plants as non-living.

But how about college students? Well, it appears that they too make mistakes, even with all that formal education: The volunteers in the study were much more hesitant in classifying plants, suggesting that they had to slow down to deliberately overrule their naïve taxonomy; and they also made more outright errors. They were also slower to size up moving things in general, and non-living natural things—suggesting that movement and naturalness were the features that stymied them.

To be fair, these weren’t biology majors. And we all know that kids can slip into college without much in the way of rigorous scientific training. But here’s the really interesting part. The psychologists ran basically the same experiment with biology professors, people who make their living teaching university students about the natural world. Indeed, the volunteers in this second study had been teaching college-level biology for a quarter century, on average, and at highly prestigious schools.

And guess what. As reported in the April issue of the journal Psychological Science, the profs did better than the undergraduates, but not as brilliantly as one might from the scientific elite. Even these experts were significantly worse at classifying plants than they were at categorizing animals. That is, even a lifetime of advanced scientific training didn’t trump the naïve impulse to view plants as artifacts.

Children may be natural-born taxonomists, but they’re not all that good at it. That’s because they have a deep-wired urge to see the world as designed and simple, and to be at the center of it all. Apparently that impulse never goes away entirely.

For more insights into the quirks of human nature, visit “We’re Only Human” at www.psychologicalscience.org/onlyhuman. Selections from the blog also appear regularly in the magazine Scientific American Mind and at www.sciam.com.

Nursing's Hidden Blessings

One in five Americans is currently taking care of another adult, voluntarily tending to an ill or frail loved one. And as the Baby-Boomer generation ages, that obligation is likely to increase. The burden takes a serious toll on caregivers, leading to poorer health and even an increased risk of death.

But what is it that actually takes the toll? Is it the physical wear-and-tear of feeding and bathing a needy relative? Is it simply that caregivers have too much work and too little time and energy? Or is it the emotional costs of watching a loved one deteriorate, or the anticipation of loss? Or all of this rolled together?

Interestingly, these possibilities have never really been sorted out—until now. A team of public health researchers, headed by Stephanie Brown at the University of Michigan, decided to explore these questions by examining the histories of more than 3000 elderly married people over several years. The couples were all living together in their own homes, but the level of neediness varied, as did the commitment of caring time. The researchers tracked the health and the survival rate of the caregivers, all 70 or older.

The results were interesting and a bit surprising. As reported in the April issue of the journal Psychological Science, those who were providing the most care for their spouses—14 or more hours a week—actually had a lower mortality rate than did those who had no care obligation. This was true regardless of the spouse’s neediness, including cognitive decline. This suggests that the health problems of caregivers may not result from the actual burden of caring. Indeed, caring may have a tonic effect under certain circumstances, which may offset the emotional toll of witnessing a spouse’s deterioration and worrying about life alone.

Why would that be? It’s not entirely clear, but it may be that the very act of giving acts as a buffer, moderating the untoward physical consequences of chronic stress, including immune dysfunction. It’s also possible that the hormones associated with helping—oxytocin, for example—actually help the body’s cells repair and store nutrients. Whatever the mechanism, it appears that nurturance is a blessing at the microscopic level.

For more insights into human nature, visit the “We’re Only Human” blog at www.psychologicalscience.org/onlyhuman. For more on healthy aging, see Wray Herbert’s recent “Mind Matters” column at Newsweek.com.

A Moral Thermostat?

Much of the immorality in the news these days has to do with greed: Wealthy financiers running Ponzi schemes, presidential aides cheating on their taxes, industrialists spoiling the environment. There appears to be a widespread erosion of any sense of social responsibility.

What’s going on with these people? Are they simply bad people? Are our educational and religious institutions failing? Are the rewards of being a good and honest man simply not enough to curb our darker impulses? Or are we all both sinners and saints, depending on the circumstances?

Psychologists have been looking into these questions, specifically the idea that we all toggle back and forth constantly between righteousness and immorality. Is it possible that we have a set point for morality, much like we do for body weight? Three Northwestern University psychologists recently explored this question in the laboratory, with some intriguing results.

Sonya Sachdeva, Rumen Iliev and Douglas Medin had the idea that our sense of moral self-worth might serve as a kind of thermostat, tilting us toward moral stricture at one time and moral license at another, but keeping us on a steady track. They tested this by priming volunteers’ feelings of moral superiority—or their sense of guilt—and watching what happened.

In one experiment, for example, they had the volunteers write brief stories about themselves. Some were required to use words like generous, fair and kind, while others wrote their stories using words such as greedy, mean and selfish. This was the unconscious prime, well known to activate feeling of either righteousness or regret. Afterward, all the volunteers were given a chance to donate money to a favorite charity; as much as $10 or as little as zero. The volunteers didn’t know their charity was being measured as part of the experiment, and the results were unambiguous. Those who were primed to think of their moral transgressions gave on average $5.30, more than twice that of controls; those who were primed to feel self-righteous gave a piddling $1.07.

These results suggest that when people feel immoral, they “cleanse” their self image by acting unselfishly. But when they have reason to feel a little superior, that positive self image triggers a sense of moral license. That is, the righteous feel they have some latitude to stray a bit in order to compensate. It’s like working in a soup kitchen gives you the right to cheat on your taxes later in the week.

The psychologists wanted to double check these findings, and they did so in the context of the environment. That is, do the same feelings of moral superiority and moral transgression shape the trade-offs we make between self-interest and the health of the planet? They used the same primes, and then had all the volunteers pretend they were managing a manufacturing plant. As managers, they had to choose how much they would pay to operate filters that would control smokestack pollution. They could simply obey the industry standard, or they could do more or less; that is, choose social responsibility or choose to cheat the common good.

The results, reported in the April issue of the journal Psychological Science, were clear. Those who were feeling morally debased were much more communitarian, spending more money for the sake of clean skies. The morally righteous were stingy, and what’s more, they took the view that plant managers should put profits ahead of green concerns. They saw it as a business decision, not an ethical choice.

So it appears that our inner moralist deals in a kind of moral “currency.” We collect chits through our good deeds, and debts through our transgressions, and we spend our chits to pay off our moral debts. That way, we keep the moral ledger balanced.

For more insights into the quirks of human nature, visit “We’re Only Human” at www.psychologicalscience.org/onlyhuman. Excerpts from the blog also appear regularly in the magazine Scientific American Mind and at sciam.com.