This is the 2007 version. Click here for the 2017 chapter 14 table of contents.

Backing up a Legal Claim

Psychologists are sometimes called upon to do detailed research involving memory or perception, to back up or contradict a courtroom argument. For example, a team was called into the case of Processed Plastic v. Warner Communications (1982).

How did social scientists help in a suit about a toy plastic car?

Warner Communications owned The Dukes of Hazzard television series. They allowed several toy companies to produce replicas of a car (the General Lee) used by the heroes of the series. The Processed Plastic Company was not one of those companies, but it began to sell a toy car that looked like the General Lee. In court, Warner produced a survey of children questioned in random groups at shopping malls. The researchers showed that 82% of the children shown a Processed Plastic car identified it as "the Dukes of Hazzard car." The trial court decided, and an appellate court agreed, that these data showed Processed Plastic had infringed on Warner's trademark rights by creating consumer confusion (Monahan & Walker, 1988).

How did a psychologist help two men who confessed to a burglary?

Arens and Meadow (1956) reported a case in which two men signed a prepared confession statement after arrest for a burglary. Later, both men claimed they were innocent and said they had signed the confession only after being threatened by police. A psychologist analyzed the confession and compared it to other samples of writing from the two defendants. The confession was not in their own language. The vocabulary and sentence construction was entirely different from that which the men would normally use. After a psychologist testified that the confession was not in the defendant's own language, the court threw it out, not allowing it to be used in court. The judge ruled that the confession showed "evidence of fabrication or fraudulent alteration by outsiders" (Arens and Meadow, 1956).

How did a psychologist attempt to help motorcyclists arrested after an accident?

Haward (1969) described a case in which a policeman in England said he jotted down the license plate number of four motorcyclists who passed him going 60 miles per hour, just before dawn. Later they were involved in an accident, and the charges against them were serious because they had been observed speeding. The defense attorneys maintained that the policeman could not possibly read four license plates at a distance of 65 yards in the 3.5 seconds it would take for the cycles to pass. A psychologist set up an experiment in which the conditions were duplicated. Subjects playing the role of the policeman failed to perceive three of the four license numbers.

What error did the psychologist make, and what is the moral of the story?

As it turned out, there was a fatal flaw in this duplication. It used stationary (motionless) targets. The judge was swayed by another expert, introduced by the prosecution, who cited a physiology textbook which said vision was better with moving than stationary targets. The moral of the story is that, if you are hired by a legal team to give expert testimony, you better get it right. Otherwise, you will be humiliated by another expert.

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