We're all irrational and susceptible to collective insanity

You may believe you’re highly rational. I perceive myself to be highly rational too. But the evidence is clear: Our memories and our reasoning process are highly vulnerable to our emotions and preconceptions.

And, as bad as individuals are at thinking rationally, groups are even worse because our beliefs are shaped so easily by those around us. Emotional contagion is a key reason why mobs so frequently do insane things.

Bob Herbert summarizes the depressing story — told in detail by The New Yorker — of an innocent man put to death by Texas for “murdering” his three children in an accidental fire.

A long chain of human mistakes — each making the next more likely — led to the innocent father’s execution:

  • Poorly trained fire investigators falsely imagined suspicious patterns in the fire that had no scientific basis, according to multiple world-class fire scientists

  • The D.A. pulled a motive from thin air: “With no real motive in sight, the local district attorney, Pat Batchelor, was quoted as saying, “The children were interfering with his beer drinking and dart throwing.””

  • After authorities announced that the father had set the fire, witness testimony shifted against him:

In Diane Barbee’s initial statement to authorities, she had portrayed Willingham as “hysterical,” and described the front of the house exploding. But on January 4th, after arson investigators began suspecting Willingham of murder, Barbee suggested that he could have gone back inside to rescue his children, for at the outset she had seen only “smoke coming from out of the front of the house” — smoke that was not “real thick.”

An even starker shift occurred with Father Monaghan’s testimony. In his first statement, he had depicted Willingham as a devastated father who had to be repeatedly restrained from risking his life. Yet, as investigators were preparing to arrest Willingham, he concluded that Willingham had been too emotional (“He seemed to have the type of distress that a woman who had given birth would have upon seeing her children die”); and he expressed a “gut feeling” that Willingham had “something to do with the setting of the fire.”

Dozens of studies have shown that witnesses’ memories of events often change when they are supplied with new contextual information. Itiel Dror, a cognitive psychologist who has done extensive research on eyewitness and expert testimony in criminal investigations, told me, “The mind is not a passive machine. Once you believe in something—once you expect something—it changes the way you perceive information and the way your memory recalls it.”

  • A prisoner seeking a lighter sentence came forward to testify against — i.e., lie about — the father. The prisoner claimed “he had passed by Willingham’s cell, and as they spoke through a food slot Willingham broke down and told him that he intentionally set the house on fire… It was hard to believe that Willingham, who had otherwise insisted on his innocence, had suddenly confessed to an inmate he barely knew. The conversation had purportedly taken place by a speaker system that allowed any of the guards to listen — an unlikely spot for an inmate to reveal a secret.” A transparently absurd claim, but one which may have registered with the jury, which eagerly convicted the father in less than an hour of deliberation.

  • The authorities refused to change their theories even after a world-renowned arson expert reviewed all the evidence and determined the fire was not caused by arson:

After Hurst had reviewed [fire investigators'] list of more than twenty arson indicators, he believed that only one had any potential validity: the positive test for mineral spirits by the threshold of the front door. But why had the fire investigators obtained a positive reading only in that location? According to Fogg and Vasquez’s theory of the crime, Willingham had poured accelerant throughout the children’s bedroom and down the hallway. Officials had tested extensively in these areas—including where all the pour patterns and puddle configurations were—and turned up nothing. Jackson told me that he “never did understand why they weren’t able to recover” positive tests in these parts.

Hurst found it hard to imagine Willingham pouring accelerant on the front porch, where neighbors could have seen him. Scanning the files for clues, Hurst noticed a photograph of the porch taken before the fire, which had been entered into evidence. Sitting on the tiny porch was a charcoal grill. The porch was where the family barbecued. Court testimony from witnesses confirmed that there had been a grill, along with a container of lighter fluid, and that both had burned when the fire roared onto the porch during post-flashover. By the time Vasquez inspected the house, the grill had been removed from the porch, during cleanup. Though he cited the container of lighter fluid in his report, he made no mention of the grill. At the trial, he insisted that he had never been told of the grill’s earlier placement. Other authorities were aware of the grill but did not see its relevance. Hurst, however, was convinced that he had solved the mystery: when firefighters had blasted the porch with water, they had likely spread charcoal-lighter fluid from the melted container.

Without having visited the fire scene, Hurst says, it was impossible to pinpoint the cause of the blaze. But, based on the evidence, he had little doubt that it was an accidental fire—one caused most likely by the space heater or faulty electrical wiring. It explained why there had never been a motive for the crime. Hurst concluded that there was no evidence of arson, and that a man who had already lost his three children and spent twelve years in jail was about to be executed based on “junk science.”

After the State of Texas murdered this innocent man, the state hired a famous fire scientist, Craig Beyler, who concluded that “investigators in the Willingham case had no scientific basis for claiming that the fire was arson, ignored evidence that contradicted their theory, had no comprehension of flashover and fire dynamics, relied on discredited folklore, and failed to eliminate potential accidental or alternative causes of the fire. He said that Vasquez’s approach seemed to deny “rational reasoning” and was more “characteristic of mystics or psychics.””

We must always be suspicious of our mind’s enthusiasm for believing what those around us believe and for interpreting all new information through the lens of our current beliefs and assumptions. Viewing the world objectively — as police detectives or jurors, for example — requires dissociating ourselves from the giant bag of assumptions we use to live our lives day to day. Sadly, rational, objective thinking is all too rare.

Posted by James on Tuesday, September 01, 2009