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The science behind sin

Researchers try to make sense of our darker impulses, and may just help save us from ourselves

Christoph Hitz for The Boston Globe

Most of us don't go around obsessing about the Seven Deadly Sins — most of us probably couldn’t name them — but the transgressions defined during early Christian times still cross our consciousness on a regular basis. Who hasn't worried about eating too much, or been distressed by someone else's anger.

Turns out, these “sins” are often the subjects of scientific study, albeit indirectly. Researchers gathered at the MIT Museum last month to describe work they've conducted relevant to the deadly seven, as part of the Cambridge Science Festival. The point of their assembly: to share some ways in which research can provide insight into these darker sides of life — and even, in some cases, hold out possibilities for redemption.

Anger: Children who have greater than normal trouble controlling their emotions are being studied at Boston Children’s Hospital by Dr. Joseph Gonzalez-Heydrich and his colleagues. Brain scans of kids with anger problems have shown that areas in the brain involved in controlling emotions, such as the prefrontal cortex, are weak. So members of the team developed a Space Invaders-like computer game that rewards players for holding their fire when friendly aliens fly by, and cuts off the game if their heart rate climbs too high, indicating too much emotional arousal.

The reasoning: If a boy had limp arms from cerebral palsy, he’d be sent to physical therapy to build strength, said Gonzalez-Heydrich, who is also an assistant professor of psychiatry at Harvard Medical School. So, why not a similar program for strengthening the systems that regulate emotional problems?


Preliminary research with 19 highly volatile children, who were receiving traditional anger control therapy, showed that their anger dropped substantially after they participated in just five game sessions. Volatile children given the same anger-control talk therapy without the game exhibited much less of a decline in anger.

Gluttony: Those early religious practitioners didn't connect gluttony to obesity, said Judith Wurtman, former director of the Research Program on Women's Health at the MIT Clinical Research Center. But today overeating and gluttony are often considered synonyms.

Fact is, most of us eat fairly regularly when we're not hungry — usually to fill an emotional need, said Wurtman, who describes this as “involuntary gluttony.’’ We're not trying to eat more, but a mood or hormonal change triggers an impulse — usually to eat carbohydrates (such as bread or pasta), which boost the feel-good hormone serotonin, said Wurtman, also author of “The Serotonin-Power Diet.”


She said that understanding this brain system is a way of taking away the feeling that you are “doing something wrong’’ when gobbling carbs. Impulse eating happens because of brain activity, Wurtman told the MIT crowd, not lack of willpower.

Envy: Peter Blake, a postdoctoral fellow in Harvard's Program for Evolutionary Dynamics, studies how children develop a sense of fairness. His explorations, he said, also shed light on envy.

In one experiment, Blake and his colleague Katherine McAuliffe gave pairs of children who didn’t know each other unequal amounts of candy. The children who received fewer pieces of candy were then given a choice of either accepting their meager allotment, or depriving both themselves and their partner of all candy.

Children ages 4 to 8 usually went for giving up their own, smaller share of candy to prevent their pair-partner from getting more. When the children who received the greater share of candy were given the same choice — give up all the goodies to be fair to both sides — they often accepted the extra candies “with great relish,” Blake said.

In adulthood, Blake said, any worker would probably take $100 from the boss, even if a colleague were given $400. “We learn to live with inequity,’’ he said.


Greed: Most Americans aren't as greedy as we tend to think, said Drazen Prelec, a professor of management at MIT. Even those who work on Wall Street may not be so bad — although he suggests that they are “tested” more by their proximity to vast wealth. “Being enterprising or motivated by money shades over to greed when other values are sacrificed,’’ he said.

A study published in February in the Proceedings of the National Academy of Sciences showed that people driving more expensive cars acted more aggressively on the road than people in low-cost models. The data suggested that a tendency to act less-than ethically by some upper-class individuals is due, at lesat in part, by their more favorable attitudes toward greed.

Like the other sins, greed is something that can be a virtue in small doses, as when a bread-winner grasps at every possible resource to support the family, he said.

Lust: Though we're supposedly more comfortable talking about sex today, many people still think about sex one way and act another, said Janet Rosenbaum, an assistant research professor at the University of Maryland's Population Research Center.

More than half of teenagers who took a virginity pledge for instance, not only didn't follow it, Rosenbaum's research showed, but the year later, the teens didn't even remember signing the pledge. Ten percent claimed to still be virgins, though they had admitted to having sexual intercourse the year before.


In more recent research, Rosenbaum said, scientists used physical evidence — semen present in a woman as long as two weeks after unprotected sex — to conclude that women also had more sex than they admitted to.

Pride: MIT literature professor Ruth Perry, an expert on Jane Austen’s “Pride and Prejudice,” chose the real-life figure of Captain Cook to explore this vice. Cook was heralded as a hero by the indigenous people of Hawaii when he visited there the first time, in 1778, and was killed by them on his third voyage.

Anthropologists have long debated why he was slain. Was it because he had been mistaken for a god on his first visit, and then defamed the god on his return? Or was it that the Hawaiians always knew he was just a man and treated him well on his first visit out of "pragmatic self-protection rather than fear and awe," in Perry’s words, then killed him when he started using force against the people and it was no longer in their self-interest to keep him around?

There were two cases of pride to this story, Perry said: that of the captain, who expected to be well treated despite his own bad behavior ­­— and the pride of contemporary anthropologists who assumed they could know the thoughts of people in 1779.

Sloth: In an interview separate from the MIT gathering, Liane Young, an assistant professor of psychology at Boston College discussed some recent research that gets at “free riders” — the type of people called “slothful” in earlier times — who benefit from being in a group but who don't pull their own weight.


“Social groups can crumble if there isn't a premium placed on being a productive member of the group,” Young said. “Nobody likes to keep tabs, but at the same time, you kind of get a sense for who's the friend who never helps anyone else move or who never returns favors.”

Moral psychologists like herself are only just starting to think of laziness as a subject of research, Young said, focusing in the past only on behaviors that cause active harm. Sloth, they've recently realized “can be just as harmful as some of the prototypical harms like assault and murder,” she said.

Drazen Prelec, who commented on greed, said he would add one more vice to the seven: Internet addiction. The Internet is appealing at first, like rich food and expensive belongings, he said. But then, “you get up and move away from the Internet, and other things around you seem drab. So what do you do? You go back to the screen.”

Karen Weintraub can be reached at Karen@Karen