by Boese, Alex
They moved sideward for several centimeters and raised their gasters steeply. Immediately a clear droplet appeared at the gaster tip which rapidly grew and fell down within a few seconds.
The ants were peeing the water away. To make sure they were seeing this correctly, the researchers repeated the experiment, with the same results. They calculated that 3,030 pee runs were required to dry out the nest.
Such “cooperative peeing behavior” had never before been observed in ants. Moog and Maschwitz tested other species, but found none that employed the same strategy. Cataulacus muticus appears to be the only ant species that uses its bladder for flood control.
The communal peeing of Cataulacus muticus truly is a wonder of evolution. That an ant species developed such an ingenious nest-saving technique boggles the mind. Unfortunately, the same cannot be said of the communal peeing of students.
The Sweet Smell of Diapers
Feces are disgusting. People don’t like coming into contact with them, and will in fact go to great lengths to avoid them. This disgust protects us from bacterial infection. But why, psychologists Trevor Case, Betty Repacholi, and Richard Stevenson wondered, doesn’t disgust prove to be more of an obstacle to child care? Babies may be cute and lovable, but they’re also prodigious poop machines. Why don’t mothers recoil in loathing at the thought of getting up close and personal with another person’s excrement? Perhaps, the researchers theorized, some kind of “source effect” modifies the disgust reaction. Perhaps feces (and other unpleasant substances) inspire less disgust if they come from sources familiar to us, such as our own child.
To test this theory, the researchers recruited thirteen mothers to participate in a “Baby Smell Study.” This description was slightly euphemistic. The task asked of each subject was actually to sniff dirty diapers, both of her own baby and a stranger’s baby, and rate which she found less offensive.
Before the experiment began, the mothers submitted diapers freshly soiled by their babies. The experimenters had stockpiled dirty diapers from a control baby. These were stored in a refrigerator to keep them fresh, but were taken out two hours before the test and allowed to warm to room temperature. By the time the sniffing began, they were good and rank.
To ensure the mothers couldn’t identify the diapers by sight, the experimenters placed each diaper in a covered plastic bucket. The aroma wafted up through a hole in the lid. Mothers put their noses right up to the hole and took a good whiff.
The mothers participated in a total of three trials. In the first trial the diaper-bearing buckets were unmarked. In the second and third trials they bore labels identifying the diapers either as those of the mother’s child or of “someone else’s baby.” However, in one of the trials these labels were incorrect.
After smelling the stinky diapers, the mothers rated each odor on how disgusting they thought it was. The results were unequivocal. Mothers preferred the smell of their own baby’s poop. In all three of the conditions—unlabeled, correctly labeled, and incorrectly labeled—the mothers rated the odor of their own baby’s dirty diapers as less offensive than that of the other diapers. Surprisingly, this preference was most pronounced in the blind trial, where the mothers had no clue which diaper was which.
The preference was so clear-cut the experimenters briefly worried that the control baby’s diapers might have been unusually stinky. But the experimenter who handled and prepared the soiled diapers assured them this was not the case. He insisted the odor of all the diapers was “similarly intense and overpoweringly unpleasant.”
The experimenters offered two reasons why a mother prefers the smell of her own baby’s poop. Either they become used to the smell through repeated contact, or they are able to detect “some quality that signals relatedness.” Case, Repacholi, and Stevenson left it to future researchers to provide further clarification.
This experiment ultimately offers a reassuring message: 63No matter how stinky, ugly, or disgusting we are, one person will always think we’re great—our mother.
Fart-ology
Sometime in the early stone age, the first joke is about to be told.
A small group of cavemen creeps through a forest, clubs in hand. Danger lurks everywhere. They must constantly be on guard. Suddenly the caveman in the lead stops and signals his companions to be silent. They all freeze in place, straining to hear any noises made by a predator. The leader looks slowly back and forth. He signals the others to listen. And then he lets one rip. Caveman guffawing ensues.
As the story of the flatulent caveman illustrates, farts have always been the butt of jokes (so to speak). The merriment that surrounds them has tended to inhibit serious research. However, there are people who make a living studying farts. In vain they point out that excessive flatulence causes extreme discomfort and distress. Someone has to study the problem, no matter how amusing it seems to everyone else. To paraphrase a joke of more recent vintage, for most a fart is just a fart, but for fart doctors it’s their bread and butter.
As a sign of the slow advance of fart studies, not until 1991 did researchers precisely determine the normal amount of flatulence produced by healthy subjects in one day. A study conducted at the Centre for Human Nutrition at the University of Sheffield recruited ten volunteers (five men and five women) each willing to live with a “flexible gas impermeable rubber tube” inserted forty millimeters into his or her anus for twenty-four hours. The tube, held in place by surgical tape, led to a plastic bag, from which no gas could escape. The researchers made sure of this:
The competence of this gas collection system was validated in two volunteers who submerged the lower parts of their bodies in warm water for an hour during which time there were no detectable leaks (bubbling) and gas was collected in the bags.
The subjects ate a normal diet supplemented by two hundred grams of baked beans, to ensure flatus production. Whenever the need to defecate arose, subjects closed off their bag, removed the tube, did their business as quickly as possible, and reinserted the tube. After a day of collection, the gas volume was measured. The median volume came out to 705 milliliters. An average of eight episodes of flatulence were reported. This translated to a median volume of 90 milliliters per episode. The women and men expelled equivalent amounts, proving the equality of the sexes, at least in this matter.
Even more shocking, it was not until 1998 that science identified the exact gases responsible for flatus odor. Dr. Michael Levitt of the Minneapolis Veterans Affairs Center used the same rectal-tube-and-bag system as the 1991 study to collect flatus from sixteen healthy subjects who ate pinto beans the night before to enhance production. Samples were then drawn from the bags via syringe and given to two judges to rate for intensity:
64In an odour-free environment, the judges held the syringe 3 cm from their noses and slowly ejected the gas, taking several sniffs. Odour was rated on a linear scale from 0 (“no odour”) to 8 (“very offensive”).
And you think your job sucks.
Odor intensity correlated with high levels of sulfur gases: hydrogen sulfide, methanethiol, and dimethyl sulfide. These gases were isolated and presented individually to the judges, who described them, respectively, as “rotten eggs,” “decomposing vegetables,” and “sweet.” Therefore Levitt could positively identify hydrogen sulfide as the gas that causes real stinkers. The sickly sweet kind of wiffies, by contrast, are due to an excess of dimethyl sulfide.
Intriguingly, Levitt’s study did find a difference between men and women. The women’s farts “had a significantly higher concentration of hydrogen sulfide (p<0.01) and a greater odour intensity (p<0.02) than did that of men.” But the men held their own by producing a greater volume of gas overall. So, for now, we can still call this battle of the sexes a draw.
CHAPTER NINE
Making Mr Hyde
Human nature has two sides—good and evil. What causes one side to grow stronger than the other? For Robert Louis Stevenson’s character Dr. Henry Jekyll, it was a salt containing an �
��unknown impurity.” When Jekyll mixed this salt into a solution and drank it, he transformed into the murderous Mr. Hyde. Many real-life researchers have shared Jekyll’s—and Stevenson’s—fascination with humankind’s wicked ways. They have studied what causes people to become rude, antisocial, overly aggressive, and cruel. Unnervingly, the answers they come up with rarely involve anything as elaborate as crystalline salts. Scientists have discovered that to bring out the worst in a person, it usually suffices to place him or her in the right situation. As Philip Zimbardo, whom we shall meet later in this chapter, once observed, “Any deed that any human being has ever done, however horrible, is possible for any of us to do—under the right or wrong situational pressures.” Of course, the same is true in reverse. Given the right situation, any person can be turned into a saint. And many researchers do study the causes of altruistic behavior. But let’s be honest—the villains are always more interesting.
Shocking Obedience
A nervous-looking man in a tight-fitting white T-shirt leans forward and speaks into the microphone. “Learner, what is your answer?”
There is no reply. After a few seconds, the man repeats the question more forcefully, “Learner, what is your answer?”
Suddenly a voice shouts through the wall, “I refuse to answer. Let me out of here.”
“You’ve got to answer, otherwise you get a shock.”
“I won’t answer. You can’t hold me here. Get me out. Get— me—out—of—here.”
The man turns in his chair and gazes imploringly at the lab-coat-wearing researcher seated behind him. “I don’t think he’s going to answer.”
The researcher calmly replies, “If the learner doesn’t answer in a reasonable time, consider the answer wrong.”
“But he’s yelling in there. He wants out.”
“Please continue.”
“Maybe we should check in on him. He said that he had a weak heart.”
“The experiment requires that you continue.”
The man sighs and turns back around. He stares at the instrument panel in front of him. The panel displays a row of thirty switches. Each switch is marked with a voltage level, from 15 volts on the far left, progressing upward in increments of 15 to 450 volts on the far right. Beneath the switch marked 315 volts is a warning: EXTREME INTENSITY SHOCK. The man carefully places his finger on this switch. Then he removes it. Once again he turns to face the researcher.
“I don’t want to be responsible for killing a man.”
“The responsibility is mine. Please go on.”
The man shakes his head as though unsure. A hollow, fearful look flickers through his eyes. He shrugs his shoulders, turns back around, and mutters, “Well, that’s that.”
He leans forward and speaks into the microphone, “Learner, your answer is wrong.” Then he presses the switch. A bloodcurdling scream shakes the walls.
Would you torture or kill an innocent victim on the command of a stranger? When asked this question, almost everyone says no. But almost everyone is wrong. Stanley Milgram’s obedience experiment, conducted at Yale University in the early 1960s, demonstrated that the average person is capable of doing horrendous things, especially when told to do so by someone wearing a white lab coat.
Milgram dreamed up his experiment while thinking about the Holocaust. Why was it, he wondered, that German citizens obeyed orders to send millions of Jews to death camps? Was there some quirk in the German character that made these citizens peculiarly obedient to authority? Or is such obedience a common feature of human psychology? If ordered, would Americans have done the same thing? To find out, Milgram decided to place randomly chosen subjects into a situation in which an authority figure would ask them to commit increasingly repellent acts of cruelty. The researcher would not coerce them. Subjects could stand up and leave at any time without consequence. Only a verbal command would be given: “Please go on . . . The experiment requires that you continue . . . You have no other choice, you must go on.” How would people respond to this request?
Milgram’s subjects were utterly ordinary people—postal clerks, teachers, salesmen, factory workers. He recruited them by placing an ad in a newspaper, offering four dollars to anyone willing to participate in an hour-long “scientific study of memory and learning.”
When a subject showed up at the Yale Interaction Laboratory, where the experiment was conducted, he was led through a series of elaborately staged events. First, a young, serious-looking researcher met him and introduced him to a man described as a second volunteer—a pleasant-looking, round-faced accountant in his late forties. Both the researcher and the second volunteer were actors who had carefully rehearsed the parts they would play during the next hour. Milgram was hidden behind a one-way window, observing everything that happened.
The young researcher provided the subject with a false explanation of the experiment. He said it was designed to examine the effect of punishment on learning. One volunteer would serve as a “learner.” He would attempt to memorize a series of word pairs. The other would be a “teacher.” He would read the word pairs to the learner. The researcher stressed the next point—the teacher would operate a shock generator. Each time the learner gave a wrong answer, the teacher would administer punishment by flipping a switch on this machine and giving the learner a shock. The shocks would increase in intensity each time an incorrect answer was given.
The two volunteers drew straws to determine who would be the learner and who the teacher. The fake volunteer always got to be the learner. The researcher then made a show of strapping the learner into an electric-chair apparatus—applying electrode gel to his wrists and tightening the restraints to prevent movement. Looking nervous, the learner asked whether the shocks could aggravate a heart condition he had. The researcher dismissed this concern: “Although the shocks can be extremely painful, they cause no permanent tissue damage.”
Next, the researcher led the subject into an adjacent room where the voltage panel was housed and showed him how to operate the machine. The teacher settled himself in front of the panel. The researcher sat behind him, across the room, and the experiment began.
It always started calmly. The teacher read out a series of word pairs: blue/box, nice/day, wild/duck. Then he read the first word of one of the pairs along with four other terms. Blue: sky, ink, box, lamp. He waited for the learner to identify the corresponding term.
The learner aced the first few pairs. The subjects must have imagined there would be no need to explore the horrors waiting at the far right of the panel. But the word pairs became more challenging, and the learner began making mistakes. One error followed another. “Incorrect,” the teacher would say, and flip a switch on the voltage panel. Next time the shock was slightly stronger. The time after that it was stronger still.
When the teacher pressed the 75-volt switch, the learner let out a distinct “Ugh” that could be heard through the wall. At 120 volts the learner’s reaction became more animated. “Hey, this really hurts,” he shouted. By 150 volts the learner was screaming to have the experiment stopped and to be let out. The cries of the learner came from a tape recorder. No one was actually being shocked. But the teachers didn’t know that. For them, the screams were terrifyingly real.
Many of the teachers began to sweat and tremble. They bit their lips and dug their fingernails into their palms. Some of them laughed hysterically. All of them looked to the experimenter for guidance. What should I do now? The researcher offered calm reassurances and urged them to proceed. “Please go on,” he would say. “The experiment requires that you continue.”
This was the moment of truth. How far up the panel would the teacher progress? Would he go to 200 volts? 300? 400? When would he push back his chair and say, “No more”? Or would he never do this? Would he press the switches all the way up to 450 volts?
Before he conducted the experiment, Milgram anticipated that virtually no one would go all the way to the end of the panel. Psychiatrists he polled agreed with this
prediction. They forecasted that only one subject in a thousand would administer the highest shock. But the actual behavior of the subjects shattered these expectations. Almost two-thirds of the teachers never disobeyed the experimenter. They agonized and sweated and shook, but they kept pressing the switch. They pressed the switch after the learner started screaming, after he yelled out that his heart was weak, and after he screamed in agony to be let out. They kept pressing the switch after the learner received 330 volts and fell into an eerie silence, apparently unconscious or dead. They pressed the switch all the way up to 450 volts, and then they kept pressing it until, finally, the researcher told them to stop. These were not serial killers or sadists. These were just average Americans, who were apparently willing to kill an innocent person because a man in a white lab coat told them to. Years later, during a CBS 60 Minutes interview, Milgram glumly concluded:
I would say, on the basis of having observed a thousand people in the experiment and having my own intuition shaped and informed by these experiments, that if a system of death camps were set up in the United States of the sort we had seen in Nazi Germany, one would be able 65to find sufficient personnel for those camps in any medium-sized American town.
Milgram tried numerous variations of the experiment, searching for the limits of obedience. He discovered that the proximity of the victim had a powerful effect on compliance. If subjects could neither see nor hear feedback from the victim, obedience was almost total. If they could hear only a thumping on the walls, compliance was 65 percent. But if the two people were in the same room, and the subject had to physically press the victim’s hand onto a metal plate to give him a shock, compliance dropped to 30 percent. Of course, 30 percent is still dismayingly high. Other variables, such as gender, had little effect on the results. Women proved just as willing as men to shock the victim.