Facial Recognition More Accurate when Whole Person Shown in Photos

Subtle body cues help people identify certain things about different facial clues and body characteristics.

According to a recent study by researchers at the University of Texas at Dallas, humans rely specifically on non-facial clues, including body shape and build, in order to identify those in challenging viewing conditions, such as poor lighting, etc.

"Psychologists and computer scientists have concentrated almost exclusively on the role of the face in person recognition," lead researcher Allyson Rice said, via a press release. "Our results show that the body can also provide important and sometimes sufficient identity information for person recognition."

Throughout several experiments, researchers asked college-age participants to study images of two people side-by-side and identify whether the images showed the same person. Some pairs looked similar while others showed different people. The researchers used a computer face recognition system in order to find pairs of pictures that match facial characteristics without too much difficulty for identification.

Overall, participants were able to accurately discern whether certain images showed the same person and whether they were provided with complete images that showed both the face and body. Participants were just as accurate at identifying people in the image pairs via the faces that were blocked out and only when the bodies were shown. However, similarly, the computer-based face recognition system had trouble identifying images of subjects' faces without their bodies.

To test the theory further, the researchers used eye-tracking equipment in order to determine where participants were actually looking. They found that participants spent more time looking at the body whenever the face did not provide enough information to identify the subjects.

 "People's recognition strategies were inaccessible to their conscious awareness," Rice said, via the release. "This provides a cautionary tale in ascribing credibility to people's subjective reports of how they came to an identity decision."

Dr. Alice O'Toole, Aage and Margareta Møller Professor in the School of Behavioral and Brain Sciences, has worked on facial recognition for over 15 years and supervised the project.

"Given the widespread use of face recognition systems in security settings, it is important for these systems to make use of all potentially helpful information," O'Toole said. "Our work shows that the body can be surprisingly useful for identification, especially when the face fails to provide the necessary identity information."

More information regarding the study can be found via the journal Psychological Science.