What is the relationship between law and psychology?

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The legal decisions made by juries are intended to be uncontaminated by evidence not presented within the court case. Jury behavior and the preconceived ideas that jurors carry into the courtroom reflecting their attitudes, opinions, and personal experiences have been recognized as standard components of trial preparation.
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The study of psychology and law, specifically decision making by a jury, is a subset of social psychology. A man might be sitting in his living room watching television when, all of a sudden, a police officer knocks on his door, asks him to step outside, and then informs him that he is being arrested on suspicion of burglary. He claims that he is innocent, but six months later he finds himself on trial for this crime in front of a jury. Should it make any difference to the jury whether he has a good or bad character, whether he is attractive or unattractive, or whether he is white, black, or Latino? The US legal system is designed to yield objective, unbiased decisions based on a set of rules and procedures intended to focus on evidence presented at the trial. Yet Clarence Darrow, one of America’s most famous lawyers, bluntly saw it otherwise: “Jurymen seldom convict a person they like, or acquit one that they dislike. The main work of the trial lawyer is to make a jury like his client, or, at least, to feel sympathy for him; facts regarding the crime are relatively unimportant.” Research in the field of forensic psychology confirms Darrow’s 1933 statement by indicating that human beings do not always conform to such idealistic principles as complete objectivity. Though moral character, lifestyle, attractiveness, race, and related factors have little, if anything, to do with the evidence presented in a given case, research shows that they nevertheless affect the outcome of both real and simulated trials.

The field of psychology and law is continually expanding. Research has focused on such topics as jury selection and jury functioning, social influence as it occurs in the courtroom, the deterrence value of capital punishment and the length of jail sentences, the validity of expert witnesses, and the effect of memory on eyewitness identifications. These areas of psychological application to the legal arena provide a wealth of information that not only will make people aware of potential problems within the judicial system but also will, it is hoped, help provide solutions to the make system as unbiased and objective as possible.

Jury Psychology

In trying to persuade a jury, a lawyer must discover jury preferences concerning the verdict or the issue to be decided in the case even before the jury is impaneled. Thus, the voir dire examination in which prospective jurors are questioned on their biases or prejudices is of extreme importance. Psychologists have shown in jury research that people decide between alternative explanations of someone else’s behavior by using attitudes already established. These attitudes concern the behavior under evaluation and the person being judged. This psychological insight about the importance of prior attitudes is the basis for trial strategy in general and for specific persuasion strategies and techniques in individual cases. The main objective of jury attitude research is to identify attitudes and values that determine which case facts or issues jurors will find most salient, how they will perceive the evidence gathered on those issues, and how those perceptions are likely to influence their decisions about the case. Moreover, in most research on juror decision making, it was found that jurors’ decisions tend to be determined by groups or clusters of attitudes related to the decision.

An example of a powerful but supposedly irrelevant variable is the moral character or lifestyle of the person on trial. A study by David Landy and Elliot Aronson in 1969 provided support for this claim when people acting as jurors in a simulated courtroom read facts about a negligent homicide case in which a pedestrian was run over and killed on Christmas Eve. Mock jurors read either positive or negative character descriptions of the defendant. In the positive character case, the defendant was described as a widowed insurance adjuster going to spend Christmas Eve with his son and daughter-in-law. In the negative character case, the defendant was described as a janitor, twice divorced, possessing a criminal record, going to spend Christmas Eve with his girlfriend. Mock jurors were asked to judge whether the defendant was guilty or innocent and, if guilty, to decide how many years he should spend in jail. When the person on trial was described as having a positive character, mock jurors sentenced him to two years in jail; when he was described as having a negative character, they sentenced him to five years in jail. This clearly suggests that the lifestyle and moral character of people on trial do dramatically influence jury decisions.

The attractiveness of the person on trial has also been found to affect the verdict reached by jurors. Michael Efran in 1974 wondered whether physical attractiveness might bias students’ judgments of another student who was accused of cheating. He had college students act as school jurors. Students received a photograph of the fellow student and a written description of the cheating case. All students read the same case description. Half had an attractive photograph attached, whereas the other half saw an unattractive photograph. Those with the attractive photograph attached judged the student to be less guilty than did those with the unattractive photograph. For those found guilty of the crime, more severe sentencing was recommended for the less attractive photograph group. Evidence that attractiveness affects jury decision making is found not only in simulated, but also in real court cases. John Stewart in 1980 asked observers to rate the attractiveness of seventy-four male defendants tried in Pennsylvania. When he later examined the court records, he found that the more attractive defendants received the lighter sentences. Once convicted, the more attractive defendants were twice as likely to avoid prison as those who were less attractive.

Although attractiveness often helps, there are circumstances under which good looks can actually hurt a person on trial. In 1975, Harold Sigall and Nancy Ostrove found that when mock jurors judged a woman accused of stealing $2,200 they were more lenient in their sentencing decisions when she was attractive than when she was not. When she was said to have swindled the money by charming a middle-aged man into making a phony investment, however, the beautiful defendant was sentenced more severely than her less-attractive counterpart. Apparently, people react quite negatively toward someone who uses his or her appearance to commit a crime.

The race of the person on trial also seems to affect the jury decision process. Stewart found that nonwhite defendants were more likely to be convicted than were whites for comparable crimes. Further, the convicted were much more likely to be sent to prison if they were nonwhite than if they were white. Louis Cohen, Laura Gray, and Marian Miller in 1990 had white students act as mock jurors in a burglary case. They all read the same burglary case, but the race of the person on trial varied among black, Latino, and white. When the defendant was black or Latino, a more severe sentence was awarded than when the defendant was white. Although the race of the defendant should theoretically be irrelevant to a court case, it does, in fact, appear to affect the verdict.

Much of the psychology associated with legal decision making is centered on trial tactics or strategy. The key to courtroom persuasion is understanding what jurors feel, know, and believe and providing them with information consistent with those predispositions. Jury persuasion is really strategy that depends on a trial lawyer’s ability to conceive, formulate, and convey information with which a jury will agree. This technique demands sophisticated insight into the complexities of human psychology combined with instincts, judgment, and oratory skills. Lawyers must act as advocates, shaping the argument in a fashion most favorable to their position. The ideas or premises jurors bring with them into the courtroom constitute what psychologists call cognitive structures. Cognition pertains to what people know; cognitive structures consist of what people think they know. Jurors are found to be inflexible because their cognitive structures act as a mechanism through which they admit information consistent with what is already there. Therefore, most jurors strive to reach verdicts that do not conflict with their cognitions (beliefs, attitudes, opinions, or values) at the beginning of the trial. Jurors’ perceptions of the trial process and their ultimate decisions are largely determined by their preexisting cognitions, which interpret, distort, or reinforce the information presented during the trial. In short, jurors view the evidence presented at the trial through their own value systems and the predisposed beliefs that they bring with them into the courtroom.

Attitudes and Value Systems

The main objective of jury attitude research is to identify attitudes and values that determine which facts or issues in the case the jurors will find most salient, how they will perceive the evidence presented to substantiate those issues, and how those perceptions are likely to influence their decisions about the case. Most psychologists agree that attitudes consist of three components: affect, cognition, and behavior. Affect refers to a person’s emotions, feelings, and “gut instincts” about something. Cognition refers to perceiving, thinking about, and interpreting information related to an object, person, or event. Behavior refers to the intention to act in ways that are consistent with an attitude. These three components are closely related. Attitude formation is acquired over time in three ways: It is learned from others, it is developed through experience, or it is the product of self-observation. Attitude salience refers to the strength with which attitudes are held. The way to determine what attitudes jurors hold and the salience of these attitudes is to undertake pretrial research focusing on what kinds of jurors hold which attitudes, their composition, and salience.

Attitudes linked to people’s key values play a significant role in shaping how they react to events both inside and outside the courtroom, including how jurors think and feel about the entire trial process and their decisions. Most attitudes are developed over a lifetime of experience with parents, friends, colleagues, teachers, books, television, and other direct and indirect sources. Attitudes vary in the intensity with which they are held, depending on how closely they relate to some underlying core value. These attitudes are the best predictors of behavior because people tend to act in ways consistent with their values.

Juror profiles based on demographics such as gender, income, age, education, religion, and political preference are desirable because they are readily observable factors. Attitude and personality, however, are said to be better predictors of juror behavior. Affective jurors decide on an emotional rather than a rational basis. They are impulsive decision makers, who often base their decisions on what they see and hear rather than waiting until all the facts have been gathered. They tend to reformulate information until it fits into their previously held worldview or set of conclusions based on how they feel about the matter at issue. They often draw conclusions without reviewing the facts or analyzing witness testimony. Affective jurors are generally deeply devoted to religious principles or philosophies of life. They are often not college educated and conduct business based on how they “feel,” what they believe, and what “ought to be.” Cognitive jurors are orderly and logical decision makers. They seek information and are organized and fastidious. They are methodical list makers who seek out facts and information. They are often college-educated and rely on detailed instruction and precision.

Keys to Persuasion

Understanding what jurors feel, know, and believe and providing them with messages consistent with these predispositions are keys to persuasion in the courtroom. What jurors see and hear in the courtroom depends on what meaning they attach to the information provided and its relevance according to their value systems. Jurors are not computers or automatons that store information and then later retrieve it verbatim. Rather, jurors store information according to their own ideas of its importance. As a general proposition, it is agreed that jurors tend to remember best the information heard first (primacy) and last (recency). Therefore, jurors tend to retain information presented at the beginning and the end of the trial better than information presented during the middle. Jurors generally argue deductively, from the general to the particular, fitting facts to premises as they are received.

Lawyers attempt to reinforce, change, or create some specific attitude, opinion, or behavior in jurors favorable to the position they are advocating. It is a dynamic process involving the relationship between those who attempt to persuade and their audience. For lawyers to be persuasive, they must adjust their strategies and tactics to the characteristics of the jury.

Jury decisions tend not to be completely objective, and factors irrelevant to the evidence presented in the case are often considered. That is, the character, physical attractiveness, and ethnicity of the defendant, as well as other factors such as attitude similarity between the jurors and the person on trial, all seem to impact the jury’s decision-making process, despite the fact that justice should be blind to these extraneous variables.

Although lawyers make use of their clients’ attractiveness, dressing and grooming them appropriately for a court appearance, the idea of a trial as a beauty contest is not an appealing one. Means of diminishing the impact of physical attractiveness on legal decisions need to be established. Some researchers have proposed that attractiveness has been found to be less powerful if a sufficient amount of factual information is presented to the jury, if the judge explicitly reminds the jury of the basis on which the verdict should be reached, and if the jury is presented with transcripts of the testimony rather than being directly exposed to those who testify. These same factors should diminish the subjective impact of race as well.

Words should be free of double or multiple meanings. A. Daniel Yarmey points out that the testimony “Mr. Brown shot Mr. Jones” depends on the witness’s perception, memory, and communications process and ability to relate what was seen and heard. Memory and language overlap. In another example, Yarmey points out that a witness who testifies to “seeing a black face” is drawing on questions of eyesight, how much light was present, the witness’s distance from the scene, other persons present, physical features, an interpretation of what constitutes “blackness,” and other such variable factors. For a jury to accept eyewitness testimony, the credibility of the eyewitness is always at issue. This is also apparent during expert testimony, when the lay jury is asked to determine the relative merit of often technical evidence. Credibility is often a deciding factor, coupled with other considerations. Other factors affecting eyewitness performance include the duration of the event, a stress or fear factor, the age of the witness, the length of the retention interval, postevent information, and the method of questioning. A lawyer who asks a witness to relate “what happened” and then asks questions is often more successful than the lawyer who attempts to draw out facts one by one.


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