Height Perception Eyewitness tools

After high school, I worked in a tobacco store. The store was in a moderately busy area in a city with high crime. The owner of the store had been robbed in the past and he had installed security measures to deter crime and help identify criminals. One of the devices that was installed was an adhesive-backed strip that indicated height along the doors. “Height markers are used in banks, police departments, retail markets and medical institutions” to help eyewitnesses gauge the height of suspects (http://www.usbanksupply.com/index.cfm/go2/view/pID/779/n/height-markers-for-banks). Why do these strips work? How do people judge height?

According to the textbook, the perceptual system takes depth into account to help people more accurately perceive the size of objects that are far away (Goldstein, 2008, p.53). People judge size based on a person or thing in relationship to the surrounding environment (Goldstein, 2008, p.53). But how we perceive things is a mixture of what our receptors show us combined with “expectations, intent, and effort” (Clerkin, Cody, Stefanucci, Proffitt, Teachman, 2009, p. 382). What does this mean for the perception of height during robberies?

Forensic sociologist Dr. Rosemary Erikson, stated that the reason height strips were seen as necessary was that clerks frequently overestimate the height of criminals when giving descriptions (http://www.slate.com/blogs/browbeat/2012/09/17/height_strips_in_convenience_store_what_are_they_for_.html). “Anyone can look tall when they’re pointing a gun at you” (http://www.slate.com/blogs/browbeat/2012/09/17/height_strips_in_convenience_store_what_are_they_for_.html). Fear is thought to create biases in visual perception potentially associated with the anxiety of events such as robberies and assaults (Clerkin, Cody, Stefanucci, Proffitt, Teachman, 2009, p. 381).

The reality of the height marker is that it works more as a deterrent then an identification tool. Employers are responding to extensive studies by training their employees to deter would-be robbers by making eye contact and establishing a relationship (Alitzio and York, 2007, p.27). After a robbery is in progress, clerks are most often trained to cooperate and give whatever they can and not appear to attempt to identify assailants (Alitzio and York, 2007, p.27). Surveillance cameras can record a suspect’s height and description more accurately, watching them run out the door is no longer advisable (http://www.slate.com/blogs/browbeat/2012/09/17/height_strips_in_convenience_store_what_are_they_for_.html). If fact, it is most likely that the height strips are now positioned in reference to the camera and not the clerk.

The way that humans perceive the height of individuals involves the data that stimulates their receptors, the context, and the knowledge and expectations of the perceiver (Goldstein, 2008, p.53). In cases of stress, anxiety, and fear, humans have a tendency to fail or inaccurately judge heights. In stores, height markers were believed to help eyewitnesses more accurately gage the height of suspects. In reality, these height strips function as a deterrent more than a perception aid.





Clerkin, E. M., Cody, M. W., Stefanucci J.K., Proffitt, D. R., Teachman, B.A., 2009, Imagery and Fear Influence Height Perception, Journal of Anxiety Disorders, ISSN 0887-6185, 2009, Volume 23, Issue 3, pp. 381 – 386.

Altizio, A., York, D., 2007, Responses to the Problem of Robbery of Convenience Stores, Problem-Oriented Guides for Police Problem-Specific Guides Series No. 49, U.S. Department of Justice, Office of Community Oriented Policing Services

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