‘Can we trust the application of the law to humans?'

Introduction
It is important that law works correctly in society: people who committed a crime have to be punished and people who did not should not be punished. This is not always an easy process and it can go wrong at different points, which can have serious consequences for suspects. In order to describe the weaknesses in the legal system, the topics truth and perception, eyewitnesses-testimonies, and the use of juries will be addressed in this paper.

Truth and perception
To solve a certain case it is important for interviewers and jurors to determine if someone is lying or not. Different studies have proven that individuals are not better than chance-level in detecting deception (DePaulo, Stone, & Lassiter, 1985; Cited in: Meissner & Kassin, 2002). Therefore police-officers often get special training-programs to help them out with this particular problem. To explain the process of detecting lies, SDT (Signal Detection Theory) can be used. SDT separates the process in two parts, namely discrimination accuracy and response bias. Discrimination accuracy refers to “the ability of an individual to correctly detect a signal (deception) versus correctly reject its absence (truth)” and response bias refers to “the degree of evidence necessary for the individual to respond that a signal (deception) has been presented” (Meissner & Kassin, 2002, p. 471). Meissner & Kassin found that “training and experience had no significant effect on participants’ ability to accurately discriminate truth from deceit” and that it led to an investigator bias effect; this means that investigators will be more biased after training than before (2002, p. 472). This is an important finding, because this means that investigators are more confident that they can make accurate judgments, while in fact they cannot. Often interviewers are already ‘sure’ of somebody’s guilt before the interrogation and therefore the interviews are often very manipulative and persuasive (Meissner & Kassin, 2002). This can be very threatening and it can make people doubt about themselves. It even can have the consequence that people confess crimes which they have never committed.

Eyewitness-testimonies
Our justice system is for a great part based on eyewitness-testimonies, so it is important to consider these. Jurors often tend to overestimate the accuracy of eyewitnesses in their final judgments, but it has appeared that often eyewitnesses are not that accurate at all. This can be explained by the way we process memories: “to be an accurate eyewitness, a person must successfully complete three stages of memory processing: acquisition, storage, and retrieval of the events witnessed” (Aronson, Wilson & Akert, 2005, p. 530). Acquisition refers to the process by which people select what is most important information in the environment. People are never able to remember all information given in a certain situation. In fact, our accuracy to observe the unexpected is not very large. It has appeared that our ability to pick the right person out of a line-up is only about 48%, this also has to do with the fact that crimes mostly occur in circumstances which make acquisition difficult; mostly unexpected, quick and often at night (Aronson et al., 2005).
Also the retrieval of memory causes problems in recognizing the right person in a line-up. Witnesses often have the tendency to choose the person who most resembles the criminal, even if this resemblance is not very strong. This problem is also referred to “best guess” problem (Aronson et al., 2005). However, line-ups are used as a strong argument for juries. It has appeared that in fact this is the most common cause of wrongful convictions in the USA (Aronson et al., 2005).
A problem in the storage of our memory is reconstructive memory. This means that our memories can be distorted by information encountered after the event occurred. Another issue is source monitoring; the process people use to try to identify the source of their memories: Misleading questions in court has the consequence that eyewitnesses report things which were not really there, and also they might be confused to why the suspect looks familiar to them (Aronson et al., 2005).
To come back at truth and perception, it has appeared that the witness’s confidence about picking the right person is only slightly related to his or her accuracy. However, witnesses are believed to be more accurate when they are more confident. Also striking is the fact that witnesses who did not know why they recognized a certain person tend to be more accurate than people who consciously compare the persons to each other. Witnesses also can choose to lie. As told before, most individuals are not able to detect the difference between truth and deceit (Aronson et al., 2005)

Juries
In the United States the jury-system is the most common one, and therefore it is of interest to take a look to the decision-making process of a jury. “Problems can arise at each of three phases of a jury trial: the way in which jurors use information they obtain before the trail begins, the way in which they process information during the trial, and the way in which they deliberate in the jury room, after all the evidence has been presented” (Aronson et al., 2005, p. 546). An important factor which can influence jury-members is pre-trial publicity. When certain cases get a lot of media-attention, it is probable that also the jurors have picked up this information, which can make them less objective. There is evidence that the more people hear about a case in the media, the more they believe the suspect is guilty (Aronson et al., 2005). Secondly, “during a trial, jurors weigh the testimony, opinions, and facts presented to them and form an overall impression of the culpability of the defendant” (Arkes, p.626). This can be influenced by the presentation of the lawyers. The third phase, deliberation in jury room, also has impact on the decision-making. Mostly the jury’s final decision is favoured of the majority of the jury, however a minority can change people’s mind about how guilty a certain person is (Aronson et al., 2005).
According to Arkes and Mellers jurors have to make two decisions: the culpability of the defendant and how much evidence a juror requires to convict (2002). Jurors with higher thresholds in the amount of evidence needed have lower chances of false convictions, but higher chances of false acquittals. In line with the Expected Utility Theory four things can happen: correct decisions are acquitting innocent persons and convicting guilty persons, false decisions are acquitting guilty persons and convicting innocent persons. The aim for jurors should be to find the ideal threshold in order to make appropriate judgments. Acceptable is found 5% of false acquittals and 8% false convictions, which are still a lot of wrong decisions. However, it has appeared almost impossible for juries to even stay in this range. Research also has shown that juries do not have a higher chance to make the right decision than individuals (Arkers & Mellers, 2002).


Conclusion
To answer the central question ‘Can we trust the application of the law to humans’? it can be concluded that this is in fact not the case, regarding all the different phases where it can go wrong. Obviously however, we do not have another choice but to trust the application of the law to humans. Therefore it is important that we are aware of the weak points in our legal system and that this is considered in important cases. It is important not only to rely on eye-witnesses and interrogations, but as much as possible on technological evidence such as DNA and fingerprints. There is however no one-sided answer on how to resolve this problem, but making people who are functioning in this system aware of these social psychological issues at least will make a start in reducing wrong decisions.


References
Arkes, H. A. & Mellers, B. A. (2002). Do juries meet our expectations? Law and Human Behavior, 26, 625-639.

Aronson, A., Wilson, T.D., Akert, R.M. (2004) Social Psychology. (5th ed.) Garden City, NJ: Prentice Hall. 527-550.

Meissner, C. A. & Kassin, S. M. (2002). “He s guilty”: Investigator bias in judgments of truth and deception. Law and Human Behavior, 26, 469-480.