That is, in this hypothetical city, if there were 72 families with 6 children born in the following order—girl, boy, girl, boy, boy, girl—how many families with 6 children do you imagine have the birth order boy, girl, boy, boy, boy, boy? Who knows what Israeli high school students made of the strange question, but fifteen hundred of them supplied answers to it. Amos posed other, equally weird, questions to college students at the University of Michigan and Stanford University. For example:
On each round of a game, 20 marbles are distributed at random among five children: Alan, Ben, Carl, Dan, and Ed. Consider the following distributions:
I
II
Alan
4
Alan
4
Ben
4
Ben
4
Carl
5
Carl
4
Dan
4
Dan
4
Ed
3
Ed
4
In many rounds of the game, will there be more results of type I or type II?
They were trying to determine how people judged—or, rather, misjudged—the odds of any situation when the odds were hard, or impossible, to know. All the questions had right answers and wrong answers. The answers that their subjects supplied could be compared to the right answer, and their errors investigated for patterns. “The general idea was: What do people do?” said Danny. “What actually is going on when people judge probability? It’s a very abstract concept. They must be doing something.”
Amos and Danny didn’t have much doubt that a lot of people would get the questions they had dreamed up wrong—because Danny and Amos had gotten them, or versions of them, wrong. More precisely, Danny made the mistakes, noticed that he made the mistakes, and theorized about why he had made the mistakes, and Amos became so engrossed by both Danny’s mistakes and his perceptions of those mistakes that he at least pretended to have been tempted to make the same ones. “We kicked it around, and our focus became our intuitions,” said Danny. “We thought that errors we did not make ourselves were not interesting.” If they both committed the same mental errors, or were tempted to commit them, they assumed—rightly, as it turned out—that most other people would commit them, too. The questions they had spent the year cooking up for the students in Israel and the United States were not so much experiments as they were little dramas: Here, look, this is what the uncertain human mind actually does.
At a very young age, Amos had recognized a distinction within the class of people who insisted on making their lives complicated. Amos had a gift for avoiding what he called “overcomplicated” people. But every now and then he ran into a person, usually a woman, whose complications genuinely interested him. In high school he’d become entranced with the future poet Dahlia Ravikovitch: His intimate friendship with her had startled their peers. His relationship with Danny had the same effect. An old friend of Amos’s would later recall, “Amos would say, ‘People are not so complicated. Relationships between people are complicated.’ And then he would pause, and say: ‘Except for Danny.’” But there was something about Danny that caused Amos to let down his guard and turned Amos, when he was alone with Danny, into a different character. “Amos almost suspended disbelief when we were working together,” said Danny. “He didn’t do that much for other people. And that was the engine of the collaboration.”
In August 1971 Amos returned to Eugene with his wife and children and a mental pile of data, and moved into a house on a cliff overlooking the town. He’d rented it from an Oregon Research Institute psychologist on leave. “The thermostat was set on 85,” said Barbara. “There were picture windows, with no curtain. They had left a mountain of laundry, none of it clothes.” Their landlords, they soon learned, were nudists. (Welcome to Eugene! Don’t look down!) A few weeks later Danny followed with his own wife and children, and an even bigger mental pile of data, and moved into a house with something even more unsettling—to Danny—than a nudist: a lawn. Danny couldn’t picture himself doing yard work any more than anyone else could picture him doing it. Still, he was unusually optimistic. “My memories of Eugene are all of bright sunshine,” he later said, even though he had come from a land where the sun shined all the time, and, on more than half the days he spent in Eugene, the skies were more cloudy than blue.
Anyway, he spent most of his time indoors, talking to Amos. They installed themselves in an office in the former Unitarian church, and continued the conversation they’d started in Jerusalem. “I had the sense, ‘My life has changed,’” said Danny. “We were quicker in understanding each other than we were in understanding ourselves. The way the creative process works is that you first say something, and later, sometimes years later, you understand what you said. And in our case it was foreshortened. I would say something and Amos would understand it. When one of us would say something that was off the wall, the other would search for the virtue in it. We would finish each other’s sentences and frequently did. But we also kept surprising each other. It still gives me goose bumps.” For the first time in their careers, they had something like a staff at their disposal. Papers got typed by someone else; subjects for their experiments got recruited by someone else; money for research got raised by someone else. All they had to do was talk to each other.
They had some ideas about the mechanisms in the human mind that produced error. They set out looking for the interesting mistakes—or biases—that such mechanisms would make. A pattern emerged: Danny would arrive early each morning and analyze the answers that Oregon college students had given to their questions of the day before. (Danny didn’t believe in waiting around: He’d later admonish graduate students who failed to analyze data within a day of getting it, saying, “It’s a bad sign for your research career.”) Amos would turn up around noon and the two of them would walk down to a fish and chips place no one else could stand, eat lunch, and then return and talk the rest of the day. “They had a certain style of working,” recalls Paul Slovic, “which is they just talked to each other for hour after hour after hour.”