Friends of the Forensic Sciente Club, this week we present the paper “’Anyone who commits such a cruel crime, must be criminally irresponsible’: context effects in forensic psychological assessment” by Rassin, E. (2021), in which the author carries out a study to know how contextual data affects the judgement of forensic psychologists when they have to make a criminal expert report.
We know that criminal procedures are different in each country because they all have their own legal system, but in general, something that is crucial for the judge or jury is to determine if the suspect has committed a crime or not.
When there is conflicting evidence, this can be a difficult task. For this reason, the help of expert experts is usually used.
We think that these people will present ideas that are scientifically analyzed and always objective. However, these expert reports have been shown to be prone to error and bias, as they are produced by people, and we all make mistakes.
In fact, there is a lot of literature on how biases affect experts. For example, they may be vulnerable to loyalty bias, that is, the tendency to produce reports that are favorable to the party that has hired them.
But beyond that, forensic confirmation bias may exist. In short, it would be a bias through which beliefs, expectations and situational context would influence the collection, perception and interpretation of evidence.
This last component of forensic confirmation bias is called the context effect. In other words, elements of the context that should be considered irrelevant to make the decision are sometimes overestimated.
An experiment cited in the article was conducted in 2021, which found that for a sample of 133 forensic pathologists, the gender and age of the caregiver of a child who had been found dead determined how suspicious they considered the death. If the caregiver was the child’s mother’s African-American boyfriend, pathologists were five times more likely to label the child’s death a homicide rather than an accident, with the opposite occurring when the suspect was the child’s Caucasian grandmother.
It is true that experts provide high quality reports to make legal decisions, but we must be fair, since in addition to being experts, they are people susceptible to bias like any other.
In fact, context effects and other biases have been documented in the work of experts from all sorts of fields, including DNA analysis, fingerprint analysis, anthropological bone analysis, bite marks, bloodstains, manual writing and voice analysis, among others.
There are reasons to believe that forensic psychologists are also susceptible to bias. Forensic psychological analyzes refer, among other topics, to risk assessment, fitness to stand trial and evaluation of treatment. Furthermore, they try to answer the question of whether the suspect is criminally responsible and therefore suitable for prison, or criminally irresponsible and therefore in need of treatment in a forensic psychiatric clinic.
Chevalier found, in 2015, findings suggesting that forensic psychologists do exhibit the loyalty bias: when they do a risk assessment they tend to benefit either the defense or the prosecution in some way, depending on who has hired them.
However, the extent to which forensic psychologists are susceptible to contextual information is unknown.
The aim of this study was to test whether context effects also occur in forensic psychologists.
To do this, 60 forensic psychology students with an average age of 23 were gathered. They were asked to judge the mental state of a suspect and were divided into two groups. One of these groups received very explicit images of the case, they were told that the victims had been “cut with a knife” and they were shown a photograph of a face intended to provoke mistrust. The other group, given much more subtle images, was told that the victims had been “dismembered” and the suspect’s face shown to them was meant to create a good feeling.
It was hypothesized that they are indeed susceptible to this bias. Participants who were exposed to very explicit evidence were expected to judge the suspect’s mental state more harshly, while the opposite was true for participants who saw more subtle evidence.
Indeed, it happened as expected. The assessment of the suspect’s mental health was significantly affected by the contextual factor.
A limitation of the study was that it was not known how each type of contextual information influenced. Future research should explore this aspect.
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