Chapter 12

Law

The Social Psychology of Evidence

Overview of the American Criminal Justice System

Eyewitness Testimony

• How accurate are eyewitness accounts?• Three conclusions about eyewitness

testimony:– Eyewitnesses are imperfect.– Certain personal and situational factors

systematically influence eyewitness’ performance.– Judges, juries, and lawyers are not well informed

about these factors.

Eyewitness Testimony: Acquisition

• Refers to the witness’s perceptions at the time of the event in question.

• Factors influencing acquisition:– One’s emotional state– Weapon-focus effect– Cross-race identification bias

Eyewitness Testimony: Storage

• Refers to getting the information into memory to avoid forgetting.

• Memory for faces and events tends to decline over time.

• But, not all memories fade over time.– However, the “purity” of the memory can be

influenced by postevent information.

Eyewitness Testimony: Storage (cont.)

• Misinformation Effect: The tendency for false postevent information to become integrated into people’s memory of an event.

• If adults can be misled by postevent information, what about children?– Repetition, misinformation, and leading questions

can bias a child’s report, particularly for preschoolers.

Biasing Eyewitness Reports With Loaded Questions

Eyewitness Testimony: Retrieval

• Refers to pulling the information out of storage when needed.

• Factors affecting identification performance:– Lineup construction– Lineup instructions to the witness– Format of the lineup– Familiarity-induced biases

Courtroom Testimony of Eyewitnesses

• Eyewitness testimony in court is persuasive and not easy to evaluate.

• Why do jurors often overestimate the accuracy of eyewitnesses?– Lack knowledge about human memory.– Base judgments largely on witness’s confidence.

Morphing Composite Faces to Catch a Thief

Effects of Lineup and Instructions on False Identifications

The Biasing Effects of Post-Identification Feedback

Improving Eyewitness Justice

• Educate judges and juries about the science so they can better evaluate eyewitnesses who testify in court.

• Make eyewitness identification evidence itself more accurate.

What Eyewitness Experts Say in Court

What Eyewitness Experts Say in Court

The Psychology of Lie-Detection

• Polygraph: A mechanical instrument that records physiological arousal from multiple channels.

• Do the lie-detector tests really work?– Truthful people often fail the test.– The test can be faked by artificially inflating

arousal responses to “innocent” questions.

Approaches to Police Interrogations

• Pressure the suspect into submission by expressing certainty of his or her guilt.

• Befriend the suspect.

The Nine Steps of Interrogation

False Confessions

• May confess merely to escape a bad situation.• Internalization can lead innocent suspects to

believe they might be guilty of the crime.• Two factors can increase the risk of false

confessions:– Lack of a clear memory of the event in question– Presentation of false evidence

Factors That Produce False Confessions

Do Guilty Expectations Produce False Confessions?

Confessions and the Jury:An Attributional Dilemma

• Juries are powerfully influenced by evidence of a confession, even if the confession was coerced.– Fundamental attribution error revisited.

• A jury’s reaction can be influenced by how confession evidence is presented.

Jury Decision Making

Jury Selection

• Voir dire is the pretrial examination of prospective jurors by the judge or opposing lawyers to uncover signs of bias.

• A peremptory challenge is a means by which lawyers can exclude a limited number of prospective jurors without the judge’s approval.

Trial Lawyers as Intuitive Psychologists

• As far as trial practice is concerned, how-to books claim that the astute lawyer can predict a juror’s verdict by his or her gender, race, age, ethnic background, and other simple demographics.

Scientific Jury Selection

• A method of selecting juries through surveys that yield correlations between demographics and trial-relevant attitudes.

• Does scientific jury selection work?• Is scientific jury selection ethical?

Juries in Black and White: Does Race Matter?

• To what extent does a juror’s race color his or her decision making? Research suggests that there is no simple answer to this question.

Effects of Racial Diversity on the Jury

Death Qualification

• A jury selection procedure used in capital cases that permits judges to exclude prospective jurors who say they would not vote for the death penalty.

• Are death-qualified juries prone to convict?

The Courtroom Trial

Nonevidentiary Influences: Pretrial Publicity

• Does exposure to pretrial news stories corrupt prospective jurors?

• Why is pretrial publicity potentially dangerous?– Often divulges information that is not later

allowed into the trial record– Issue of timing

Contaminating Effects of Pretrial Publicity

Nonevidentiary Influences: Inadmissible Testimony

• Why do people not always follow a judge’s order to disregard inadmissible evidence?– Added instruction draws attention to the

information in controversy.– Judge’s instruction to disregard may arouse

reactance.– Jurors want to reach the right decision, so it is

hard to ignore information that seems relevant to the case.

Nonevidentiary Influences: The Judge’s Instructions

• To make verdicts adhere to the law, juries are supposed to comply with the judge’s instructions.

• Do jurors understand their instructions?• What about the timing of the instructions?• What if the jury disagrees with the law?– Jury nullification

Jury Deliberation

Leadership in the Jury Room

• A person is more likely to be chosen as foreperson if the person:– Is of higher occupational status or has prior jury

experience– Is a male– Is the first person who speaks– Is sitting at the head of a rectangular table

• Forepersons act more as the jury’s moderator rather than its leader.

The Dynamics of Deliberation

• In criminal trials, deliberation tends to produce a leniency bias favoring the defendant.– leniency bias is the tendency for jury deliberation

to produce a tilt toward acquittal.

• How do juries resolve disagreements?– A combination of informational and normative

influence

Jury Deliberations: The Process

The Road to Agreement: From Individual Votes to a Group Verdict

Jury Size

• How does jury size affect the decision-making process?– Possible lack of allies in smaller juries may make it

harder to resist normative pressures.– Smaller juries are less likely to represent minority

segments of the population.– Smaller juries are more likely to reach unanimous

decisions after shorter deliberation periods.

Less-Than-Unanimous Verdicts

• Weakens jurors who are in the voting minority.

• Breeds closed-mindedness.• Short-circuits the discussion.• Leaves many jurors uncertain about the

decision.

Posttrial

To Prison and Beyond

The Sentencing Process

• People disagree on the goals served by imprisonment.– Incapacitate offenders and deter them from

committing future crimes?– Exact retribution for misdeeds?

• Common public complaint is sentencing disparity.– Sentencing disparity is the inconsistency of

sentences for the same offense from one judge to another.

The Prison Experience

• Does the prison situation lead guards and prisoners to behave as they do?

• Zimbardo et al.’s (1973) Stanford Prison Study.• How does this study inform the power of the

situation?

Perceptions of Justice

Justice as a Matter of Procedure

• Satisfaction with dispute resolution depends on both the outcome and the procedure used to achieve those outcomes.

• Important aspects of procedure:– Decision control– Process control

Which Legal System Do People Prefer?

• Adversarial Model: The prosecution and defense present opposing sides of the story.

• Inquisitorial Model: A neutral investigator gathers evidence from both sides and presents the findings in court.

• Adversarial proceedings seen as more fair and just because the method offers participants a voice in the proceedings.

Culture, Law, and Justice

• Much of research from this chapter can be universally applied– Yet there are important cross-cultural differences

• Different nations have different laws• Different cultures have different customs• Likewise, punishments for crimes also vary

Closing Statement

Closing Statement

• Through an understanding of social psychology we can now identify the problems in the legal system and even find some solutions.