- Position‹2 of 2
- No, lie detectors should not be admissible in court
- Argument1 of 4›
Lie detectors have an inherent racial bias
In several different experiments, people of color were overrepresented as failing the test when they were innocent. This means that allowing polygraphs to be admissible in court introduces another mode for racial bias into the justice system. Even worse, since results from lie detectors are presented as objective scientific findings, this bias is given legitimacy.
The argument
The objection to polygraph evidence made here is not the general one about accuracy but a specific one: the errors the machine produces are not distributed evenly across the population, and they fall hardest on black examinees. The figures come from a test examining more than 1,100 subjects' polygraph results. Among innocent candidates, only 23.5% of black participants were correctly identified as non-deceptive, against 36.9% of innocent white participants. Under the Modified General Question Test, a variant question structure, the gap widened: 14.6% of black participants were correctly identified as giving non-deceptive answers, compared with 33.3% of white participants. The relevant comparison is within the innocent group, so the disparity cannot be explained by any difference in who was actually lying. The same truthful answers were read correctly far less often depending on who gave them. The pattern is not confined to that study. In polygraph tests administered to FBI applicants between October 2008 and June 2010, Asian, Hispanic, Native American and Pacific Islander applicants were overrepresented among those failed and dismissed for failing the test — the same disparity appearing in a real selection process with real consequences for the people it screened out. The reason for excluding such evidence from court goes beyond the error rate itself. Polygraphs do not merely introduce a new avenue for racial bias into the justice system; more dangerously, they shroud it in the veil of science and authenticity. A juror can weigh a witness's prejudice, or an investigator's hunch, because both are recognisably human judgments. A machine's output invites no such scrutiny. It takes human prejudices, wraps them in science and presents them as an objective technological finding, which is harder to challenge precisely because it does not look like an opinion. Because lie detectors carry an inherent racial bias of this kind, the argument concludes, they should not be admissible in court.
Context
Research indicates that an innocent black candidate is more likely to induce a false positive polygraph reading than an innocent white candidate.
Premises
Counter-arguments
The test itself is not racially biased. It is the vessel through which examiners can project their beliefs. Therefore, it is no more vulnerable to racial biased than a jury of the defendant’s peers might be. The existing judicial system is racially biased; however, this is because racism is still in existence in wider society. No legal tool will be protected from individual prejudice, be it trial by jury, lie detectors, expert testimony, or non-jury trials overseen by a judge, as long as the margin for human error exists. Given a polygraph test’s proven ability to determine lie from truth at a better rate than behavioral analysis and guesswork, it’s evidence should be admitted in court under the understanding that any method to determine guilt is vulnerable to individual prejudice, but until we can remove the margin for human error, we cannot escape this.
Rejecting the premises
[Rejecting P3] No system for determining guilt from innocent is protected from human error. While human error exists, there will be room for an individual's racial prejudices to influence the outcome. Lie detectors are the best we have for now. Therefore, they should be admissible in court.