Tuesday, December 27, 2011

The Compliant Juror: Part V

In Parts I, II, and III of this series, I argued that jurors tend to be compliant because they are (as all people)  loath to defy authority. In Part IV, I belatedly took the trouble to show that jurors are indeed compliant, and I then actually bothered to define the term.

In this post, I will present an alternate hypothesis for juror compliance, a hypothesis other than blind obedience to authority. I will support my alternative hypothesis by writing first and mostly of craniometry, the study of skull measurements and their significance (or lack thereof). I will then make an elegant and seamless segue to compliant jurors, and my case will be made.

From The Skeptic's Dictionary, I offer the following overview of craniometry. Forgive their use of "etc." They're skeptics, not grammarians.
Craniometry is the measurement of cranial features in order to classify people according to race, criminal temperament, intelligence, etc. The underlying assumption of craniometry is that skull size and shape determine brain size which determines such things as intelligence and capacity for moral behavior. Empirical evidence for this assumption is not very strong. This fact has not hindered small-headed people from claiming they are members of a superior race or gender because the head size of their racial or gender group is larger on average than the head size of some other racial or gender group. As members of superior races and gender, these small-headed people reason that they, too, must be superior to all members of races inferior to their own and of all members of the other gender. ... 
In the 19th century, the British used craniometry to justify its racist policies toward the Irish and black Africans, whom the British considered to be inferior races. Irish skulls were said to have the shape of Cro-Magnon men and were akin to that of apes, proof of their inferiority along with black Africans. In France, Paul Broca demonstrated that women are  inferior to men because of their smaller crania. He argued against higher education for women because their small brains couldn't handle the demands. 
In the 20th century, the Nazis used craniometry and anthropometry to distinguish Aryans from non-Aryans. The Belgians used these pseudosciences, among other things, to distinguish Hutus from Tutsis in Rwanda. "In the 1930s the Belgians required everybody [in Rwanda] to start carrying an identity card classifying themselves as Hutu or Tutsi, thereby markedly increasing the ethnic distinction that had already existed"
That Hutu / Tutsi thing worked out great, didn't it?

If you want to join the exciting world of craniometry, you're going to need some tools. Here a few tools of the trade.

Where people were really going with this nonsense was brain size. The craniometricians were almost exclusively Caucasian. In the golden era of craniometry, Caucasians dominated, and they sought to justify their dominant position. They weren't heartless, insensitive, or inhumane, you see. It was simply science, simply fact. One class of people had larger brains, were more intelligent, and meant to rule. Other classes had smaller brains, were less intelligent, and were fit only for a lesser station in life.

It was only natural, therefore, that scientists who studied craniometry came from the large-brained class. They were merely recording as scientific fact, in impassive fashion, the differences in brain size among different races. Samuel George Morton was one of those scientists. An American physician and naturalist, his tool of choice was the mustard seed.

By the time he died in 1851, Morton had collected more than 1000 skulls of people from around the world. He measured the brain volume of these skulls by seeing how much mustard seed they would hold. He attempted to conduct and document his work carefully, to be as unbiased as he could. From a book to be referenced below:
Morton a Philadelphia patrician with two medical degrees -- one from fashionable Edinburgh -- provided the "facts" that won worldwide respect ... Morton won his reputation as the great data-gatherer and objectivist of American science, the man who would raise an immature enterprise from the mires of fanciful speculation. Oliver Wendell Holmes praised Morton for "the severe and cautious character" of his works, which "from their very nature are permanent data for all future students of ethnology." ... When Morton died in 1851, the New York Tribune wrote that "probably no scientific man in America enjoyed a higher reputation among scholars throughout the world, than Dr. Morton."
Yet Morton gathered skulls neither from the dilettante's motive of abstract interest nor the taxonomist's zeal for complete representation. He had a hypothesis to test; that a ranking of races could be established objectively by physical characteristics of the brain, particularly by its size.
Morton took a special interest in native Americans, both north and south. He titled his first and largest work the Crania Americana. Perhaps as a European-American scientist, he was particularly interested in justifying the treatment of native Americans by European-Americans. Of Greenland's natives, for example, he wrote:
They are crafty, sensual, ungrateful, obstinate and unfeeling, and much of their affection for their children may be traced to purely selfish motives. They devour the most disgusting aliments uncooked and uncleaned, and seem to have no ideas beyond providing for the present moment. ... Their mental faculties, from infancy to old age, present a continued childhood. ... In gluttony, selfishness and ingratitude, they are perhaps unequalled by any other nation of people.
Of the Chinese, Morton wrote:
So versatile are their feelings and actions, that hey have been compared to the monkey race, whose attention is perpetually changing from one object to another.
Of Hottentots:
... the nearest approximation to the lower animals. ... The women are represented as even more repulsive than the men.

After Morton's work, there could no longer be any reasonable doubt as to the superiority of the races. It was no longer a matter of casual observation or cultural bias. The science was settled. 

In 1977, however, science historian Stephen Jay Gould re-examined Morton's work. Gould reported his findings in several sources including one of my favorite books: The Mismeasure of Man.

I quoted previously from that book. I quote again below.
During the summer of 1977, I spent several weeks reanalyzing Morton's data. (Morton, the self-styled objectivist, published all his raw information. We can infer with little doubt how he moved from raw measurements to summary tables.) In short, and to put it bluntly, Morton's summaries are a patchwork of fudging and finagling in the clear interest of controlling a priori convictions. Yet -- and this is the most intriguing aspect of the case -- I find no evidence of conscious fraud; indeed, had Morton been a conscious fudger, he would not have published his data so openly. 
Conscious fraud is probably rare in science. It is also not very interesting, for it tells us little about the nature of scientific activity. Liars, if discovered, are excommunicated; scientists declare that their profession has properly policed itself, and they return to work, mythology unimpaired, and objectivity vindicated. The prevalence of unconscious finagling, on the other hand, suggests a general conclusion about the social context of science. For if scientists can be honestly self-deluded to Morton's extent, then prior prejudice may be found anywhere, even in the basics of measuring bones and toting sums.
Gould provided, in great detail, examples of the "unconscious finagling" that he claims littered Morton's work. Using Morton's own data, he recalculated the average brain size for Caucasians and native Americans. He found that Morton had made multiple errors and that the errors always favored Morton's pre-conceived notion about racial superiority. Morton's errors caused the Caucasian brain size to be overstated and the native American brain size to be understated. Instead of 87 versus 82 cubic inches, Gould calculated (using the same data) values of 84.45 and 83.79 cubic inches. In other words, using the same set of data, Morton found a significant difference where Gould found none at all. 

Gould categorized Morton's errors into three groups: procedural omissions, selectivity, and subjectivity. Regarding procedural omissions, Gould wrote:
Morton was convinced that the variation in the skull size recorded differential, innate mental ability. He never considered alternate hypotheses, though his own data almost cried out for a different interpretation. Morton never computed means by sex or stature, even when he recorded these data in his tabulations. Had he computed the effect of stature, he would presumably have recognized that it explained all important differences in brain size among his groups.
It is now well-recognized that body size is a first order determinant of brain size. As a scientist, Morton had the evidence for that conclusion, but failed to see or explore it. He was too focused finding proof of his preconceived notions to correct his data for effect of body size. Even today, there's no reason to believe that people the size of Bill Gates and Steve Jobs are inherently less intelligent that the average NBA player.

Regarding selectivity, Gould wrote:
Morton often choose to include or delete large subsamples in order to match group averages with prior expectations. He included Inca Peruvians to decrease the [American] Indian average, but deleted Hindus to raise the Caucasian mean.
Regarding subjectivity, Gould wrote:
Morton's measures with [mustard] seed were sufficiently imprecise to permit a wide range of influence by subjective bias; later measurements with [lead] shot, on the other hand, were repeatable, and presumably objective. In skulls measured by both methods, values for shot always exceed values for the light, poorly packed seed. But degrees of discrepancy match a priori assumptions; an average of 5.4, 2.2, and 1.8 cubic inches for blacks, Indians, and whites, respectively. In other words, blacks fared poorest when the results could be biased toward an expected result. ... Plausible scenarios are easy to construct. Morton, measuring by seed, picks up a threateningly large black skull, fills it lightly and gives it a few desultory shakes. Next, he takes a distressingly small Caucasian skull, shakes hard, and pushes mightily at the foramen magnum with his thumb. It is easily done, without conscious motivation; expectation is a powerful guide to action.
And now for promised elegant and seamless segue.

Just as Samuel George Morton was unable to recognize and control the effect of his pre-conceived notions on his science, I suggest that jurors are unable to recognize and control the effect of their preconceived notions on their jury verdicts.

Morton believed that the non-white races were mentally inferior to Caucasians. Jurors (i.e. the American public) believe that we generally don't arrest and prosecute, much less imprison, people for doing nothing wrong. After my last stint as a juror, my mother asked me what the case was about. I said it had to do with child molestation. She said: "Oh, my. I hope you convicted him." I said nothing. I let he comment hang there, uncomfortable to us both. Then she said quietly, but not convincingly: "I guess I should wait to hear the evidence."

Morton knew that, as a man of science, he was not supposed to anticipate the answer. He was supposed to allow the data to speak for itself. Jurors know that they are not supposed to anticipate a verdict. They are instructed to presume the defendant innocent, and not render a guilty verdict unless the State proves guilt beyond a reasonable doubt. All jurors take an oath to do just that, but many of them, far too many of them do not.

Morton's bias made its way into his results and was later discovered because Morton did not recognize his own bias. He published all his work, including his raw data and his methods. Gould argued that Morton's openness spoke to both his integrity and his failure to see his own bias. Similarly, when polled, jurors will freely admit they voted guilty even when the evidence failed to support such a verdict.  Once again, I repeat the critical plot below.
My alternative theory for juror compliance (and for Morton's behavior) has a name. It's called confirmation bias. I've written of it before. I'll write of it again sometime. For now, I'll turn as I frequently do to the fine folks at Wikipedia:
Confirmation bias ... is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true. As a result, people gather evidence and recall information from memory selectively, and interpret it in a biased way. The biases appear in particular for emotionally significant issues and for established beliefs. For example, in reading about gun control, people usually prefer sources that affirm their existing attitudes. They also tend to interpret ambiguous evidence as supporting their existing position. Biased search, interpretation and/or recall have been invoked to explain attitude polarization (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence), belief perseverance (when beliefs persist after the evidence for them is shown to be false), the irrational primacy effect (a stronger weighting for data encountered early in an arbitrary series) and illusory correlation (in which people falsely perceive an association between two events or situations).
In summary, I argue that jurors presume the defendant must have done something or he would not be on trial. I argue that confirmation bias then takes over. Every bit of evidence and every mannerism of the defendant is distorted by the overpowering lens of confirmation bias.

As evidence of the overpowering nature of confirmation bias, I offer a footnote on the work of Stephen Jay Gould, the noted Harvard professor who so skillfully took Samuel George Morton to task for his confirmation bias. Just this year, in June 2011, six anthropolgists reviewed Gould's review of Morton. They presented their findings in The Mismeasure of Science: Steven Jay Gould versus Samuel George Morton on Skulls and Bias. They too make all their work available for your review. If instead you trust me to summarize, press on.

Jason Lewis, et. al. find that Stephen Jay Gould suffered more seriously from confirmation bias than did Samuel George Morton, and that Gould made several of the same mistakes of which he wrongfully accused Morton. They make a compelling case that one of my intellectual paragons was just as human as the rest of us. I caution you that Lewis effectively refutes some of the very Gould quotes I used in this very post. I refer you to their article for specifics.

Who then should you trust to tell you the unvarnished, unbiased truth? Morton? Gould? Lewis? Me?

How about the judge, the police, or the prosecutor?

How about your preconceived notions?

How will you ever function again?

1 comment:

Anonymous said...

I thought of another question to ask when I thought about this post. Should the defense have the option to go first in a trial? I was trying to think if the order of the presentation would lead to more confirmation bias or less.


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