Not all confessions are created equal. In a criminal justice setting, some admissions of guilt are both sincere and corroborated — but others are not, having been coerced, given by vulnerable or underage defendants, or unreliably reported secondhand. Yet mock jury trials have shown that lay people often tend to take a confession at face value, handing down a guilty verdict without considering other potential evidence.
It’s with this in mind that Fabiana Alceste from City University of New York and colleagues question just how well people really understand the existing body of evidence on reliable, admissible confessions in a new paper in Applied Cognitive Psychology. The answer to that question could have ramifications not only for those on juries but also for the people they’re deciding whether to convict.
To examine lay beliefs, the researchers presented 151 participants with thirty statements related to interviews, interrogations and confessions, some true and some false. These statements had previously been presented to a panel of confession experts, and related to one of four areas: general principles of psychology (e.g. “compared to most adults, adolescents exhibit immaturity of judgment in their decision-making”), truth and deception detection (e.g. “trained police can distinguish between truths and lies at high levels of accuracy”), police interrogation tactics (e.g. “threats of physical violence during interrogation can lead an innocent person to confess to a crime”), and confessions (e.g. “confessions can be verified as true by the details that they contain about the crime”).
After viewing each statement, participants indicated how reliable they thought the evidence behind it was, responding with either: “the reverse is probably true”, “the evidence does not support it”, “the evidence is inconclusive”, “the evidence tends to favour it”, “the evidence is generally reliable”, “the evidence is very reliable”, or “I don’t know”. Participants also indicated whether or not they personally agreed or disagreed with each assertion, as well as stating whether or not they believed a jury would benefit from hearing testimony from an expert in a trial involving a disputed confession.
A majority of participants correctly endorsed all of the statements relating to psychological principles — the effects of reward and punishment on behaviour, adolescent decision-making and sleep deprivation, for example. Experts and laypeople were generally in agreement on these statements, though experts endorsed them at significantly higher rates.
When it came to deception detection, however, a majority of participants endorsed unsupported statements — that trained experts can accurately judge truth or lies from facial microexpressions, for example, or through non-verbal behavioural cues. The panel of experts, on the other hand, correctly rejected these propositions.
There were also some large discrepancies when it came to interrogation tactics. While 84% of participants correctly identified that torture can get innocent people to confess, only 56% believed that false claims of evidence implicating the suspect in the crime can do the same — versus 94% of experts who asserted that it can. Worryingly, significantly more participants believed Miranda rights (your “right to remain silent”) adequately protected against false confessions — 49% to the experts’ 25%.
When the team looked at beliefs about reliability of research, however, the gap between participants and experts widened further. Both laypeople and experts personally disagreed with the statement “innocent people never provide false confessions voluntarily”, for instance — but while nearly every expert indicated the research did not support the statement, many laypeople believed the evidence was still inconclusive or even supported the statement.. The same disparity was found for a number of other statements about confessions.
Almost all participants — 94% — believed that juries would benefit from hearing expert testimony. Yet they rarely answered “I don’t know” to the questions, suggesting that they were not particularly clear on their own lack of knowledge. Future research could explore this gap further by looking at participants’ confidence in each answer — working out whether people don’t know what they don’t know, in other words.
Despite the clear value of expert knowledge on confessions, many courtrooms do not accept it as admissible testimony, instead relying on juries using common sense. But that “common sense”, as this study highlights, does not always match up to the body of evidence surrounding confessions.
The team suggests that confession experts should be permitted to give testimony to juries, who may not possess reliable information about admissible evidence and instead harbour incorrect beliefs. Understanding interview, interrogation and confession isn’t just an intellectual matter — the serious ramifications that emerge from a lack of knowledge can literally be a matter of life and death.