28 September 2015

Researchers at LSBU have examined the influence of body type on eyewitness perception of crimes, and if it led to similar bias as other factors such as race, age and gender.

Participants in the study – in the Journal Psychiatry, Psychology and Law – were shown one of two short videos, depicting a violent or non-violent robbery. In one video the victim had their wallet stolen, and then was violently assaulted and knocked to the ground. The other video displayed a non-violent crime where the perpetrator took the victim’s wallet by stealth. In each case, the crime was perpetrated by a person dressed to conceal their facial features and physique.

The study participants were then asked to identify the person they witnessed committing the crime from a suspect line-up of muscular, overweight and normal suspects. The photos in the line-up had been previously manipulated so that each face in the line-up was randomly assigned a body-type, as was possible due to clever photo editing.

Unbeknownst to the participants, the true perpetrator of the crime was not offered as a suspect choice in the line-up. This resulted in the participants having to rely on judgments regarding the suspects based on their own bias.

The results found that 51% of participants accused muscular suspects of being the perpetrator in the video. This was followed by 37% of participants selecting suspects of a normal weight. Only 10% of participants identified overweight suspects as the perpetrator.

Dr Julia Shaw (pictured), Senior Lecturer in Criminology at LSBU, said: “Stereotypes about body type may be getting in the way of justice. Our findings suggest that if you are an innocent suspect of a crime but happen to be muscular, you may be at a significant disadvantage.

“Body type is often overlooked as a basis for discrimination, and has rarely been examined in legal contexts. The present research is evidence that the body type of a suspect can impact the partiality of eye-witness accounts.

“It’s surprising that this was the outcome for both of our scenarios, a violent mugging and a simple theft. We may have expected that muscular body types may have played a bigger role in the scenario involving a physical altercation, but this was not the case. Muscular men were always at a disadvantage compared to individuals of other statures, regardless of the type of crime.

“In practice this means that police may benefit from ensuring that suspects in police line-ups are matched as much as possible on body type to avoid relying on stereotypes.” Dr Shaw added.