Reading Brooks' Bests and Reexamining What We Know

How do people know what happened?  Even things they've seen themselves.  How does what other people say affect what they 'know?'   We really don't know that much about these things.  Kevin L. Leahy, an attorney who has defended corporations against asbestos personal injury claims writes about the memory of witnesses:
Cognition specialists discuss memory as a process that has three primary stages: (1) encoding; (2) consolidation and storage; and (3) retrieval. (Id.) Each step involves biological efforts within our brains to ensure that an eyewitness account is accurately retained. (May 2003 issue of HarrisMartin’s COLUMNS-Asbestos.)
He goes on to say that unlike artists or story tellers, who can fill in the details after the fact, and not necessarily accurately,
eyewitnesses have no license to stray from their understanding of past events during trial. Our system expressly demands that witnesses “tell the truth, the whole truth, and nothing but the truth.” Once the bailiff and judge forbid conscious manipulation of testimony, however, the remaining instructions are generally silent about the accuracy of the witness’ recall.
So, you might ask, where is this coming from and where is it going?  David Brooks, in the Friday, Dec. 25, 2009 NY Times gives out his Sidney Awards to the best magazine essays  of 2009.

One of his choices is a lengthy story about Todd Willingham, an unemployed auto mechanic, who was put to death in Texas for killing his three daughters by burning his house down.  All the expert witness arson evidence pointed to Willingham.  And so did the eyewitness evidence.  But a friend who came to know Willingham when he was on death row, decided to  recheck the evidence.  And what she found suggested that  some of the details the eyewitnesses gave, was revised later on, after they were exposed to what the 'experts' thought.  From the New Yorker artcle,  "Trial by Fire"   by David Grann:
The witnesses’ testimony also grew more damning after authorities had concluded, in the beginning of January, 1992, that Willingham was likely guilty of murder. 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.”