By Siouxsie Wiles 22/07/2015


Researchers from the University of Toronto have just published an interesting paper about the impact of the ‘trustworthiness’ of a person’s face on the sentence they received for committing a crime.

It’s essentially a study of the unconscious biases we associate with facial characteristics. Apparently, humans are quick to judge how trustworthy someone is – just by their face. The paper didn’t go into any details about what makes someone look trustworthy or untrustworthy so I looked around online and found the infographic below. It looks like we confer trustworthiness on features like cheekbone shape and eyebrow arc – untrustworthy faces are ones with a furrowed brow, shallow cheekbones, low inner eyebrows and a thinner chin, while trustworthy faces have more prominent cheekbones, high inner eyebrows and a wider chin.

untrustworthy faces

Previous research has shown that in hypothetical crime scenarios, faces that look more ‘criminal’ (whatever that looks like) are more likely to be found guilty, while faces that are rated as trustworthy require more evidence to be found guilty. So the question is, does this happen in the real world? To answer this, John Paul Wilson and Nicholas Rule set out to see if this unconscious bias impacts on the sentences prisoners actually received.

They used photos of the nearly 400 people on Death Row in Florida and then matched them for race with another almost 400 people serving a life sentence for first degree murder. They ended up with a final database of 742 photos, half serving life and the other half sentenced to death. The images were converted to greyscale to minimise differences in lighting and the colour of outfits the prisoners were wearing. Then over 200 people were each asked to look at about 100 of the faces and rate the trustworthiness of each face on a scale of 1-8, with 1 being most untrustworthy and 8 being most trustworthy.

What the researchers found was a statistically significant difference between the mean ‘trustworthiness’ of the people sentenced to death versus those sentenced to life in prison – people on Death Row had faces rated less trustworthy. But it’s worth noting that the effect size was small – the mean score for the Death Row prisoners was 2.76 (with a standard error of 0.03) versus 2.87 (with a standard error of 0.03) for those sentenced to life.

Next the researchers gathered photos of people listed by the Innocence Project, an organisation dedicated to exonerating wrongfully convicted people through DNA testing. They ended up with 37 people, all men, 20 of them sentenced to life imprisonment and 17 sentenced to death. Again people were asked to rate each face’s trustworthiness. And again, there was a difference between those sentenced to death and those sentenced to life imprisonment. And these were actually innocent people. Scary stuff.

So there you have it, your face determines your fate. Hope you have been blessed with prominent cheekbones and a wide chin!

I talked about this story, and the science of screams with Kathryn Ryan on Radio NZ’s Nine to Noon programme. You can listen here.

Reference:
J. P. Wilson, N. O. Rule. Facial Trustworthiness Predicts Extreme Criminal-Sentencing Outcomes. Psychological Science, 2015; DOI: 10.1177/0956797615590992