Trending Topics

Understanding the dynamics of stress, memory, and decision making

I recently had the honor of presenting at the Defense Research Institute’s (DRI) Civil Rights and Governmental Tort Liability seminar. The 275 attorneys in attendance are all litigators who defend municipalities and law enforcement officers against plaintiff’s suits. The topic of my presentation was “The Science of Human Factors and Its Application to Force Encounters.” Dr. Bill Lewinski of the Force Science Research Institute (FSRI) was originally scheduled to speak at the conference, but when he had a scheduling conflict Scott Buhrmaster, Vice President of Operations for FSRI, was gracious enough to ask me if I would be interested in taking on the challenge. In a future article I will detail the six overarching human dimensions of Attention and Perception, Arousal, Memory and Interpretation, Reaction Time, Decision Making, and Error of which I spoke, but in this article I would like to introduce the reader to Professor Matthew J. Sharps, his research, and his exceptional book Processing Under Pressure: Stress, Memory and Decision-Making in Law Enforcement.

Many are aware of the critical and often career-saving research conducted by Dr. Bill Lewinski of the Force Science Research Institute. In fact, if the reader is not a subscriber to the FSRI newsletter stop reading now and go to the web site and subscribe. It is from FSRI News #117 that I first learned of Dr. Sharps’ study. That study led me to seek out Dr. Sharps... my conversations with him, as well as his research and book, provided much of the material for my lecture at the DRI conference.

Decision Making Under High-risk Conditions
Dr. Sharps is Professor of Psychology at California State University, Fresno and he teaches cognitive psychology, cognitive neuroscience, and the history of psychology. He has published extensively on cognition, and his current research focuses on cognitive psychology in law enforcement contexts, especially eyewitness memory and decision-making under high-risk conditions. In addition, he has consulted in over 160 criminal cases, and works closely with the Fresno, California Police Department.

Dr. Sharps and his colleague, Dr. Adam B. Hess, published To Shoot or Not to Shoot: Response and Interpretation of Response to Armed Assailants in the winter 2008 issue of The Forensic Examiner. The article detailed the results of two experiments they performed at Fresno State University driven by several incidents of officers shooting unarmed suspects including the NYPD Amadou Diallo case, and an event in Tacoma Washington in 2007. In both situations, officers mistook an innocuous object in a subject’s hand for a firearm and fired in self-defense killing the individual. Sharps and Hess wanted to know how an untrained person would react if placed in the position of a police officer confronting a situation potentially involving firearms and firearm violence; and how an untrained person felt an officer should respond to a given situation involving gun violence. The outcomes were surprising enough that when I presented the study results to the attorneys present at the DRI conference I heard gasps and expressions of exasperation.

Since the reader can easily access the entire study at the FSRI web site, I will provide a synopsis of the two experiments and the results. In the first experiment, the researchers set up four scenes which were digitally photographed. The photographs depicted a potentially violent scene. The first scene depicted a male Caucasian in profile pointing a firearm. This scene was “sterile” in that the individual was alone and the scene had no distracting objects. The second scene depicted the same individual in the same stance, but distracting items were added to the environment. These included street clutter, garbage cans, and other potentially distracting items. Scene three contained all items and the individual from scene two, but added several bystanders and a “victim” threatened by the armed perpetrator. Finally, scene four was identical to scene three but the firearm was replaced with a power screwdriver.

The scenes were presented electronically to the participants for either .5 or 2 seconds. These times were chosen as they bracket the average time of a law enforcement deadly force encounter. The participants indicated whether or not they would shoot at the subject by either pressing a key on a computer keyboard or shooting a toy suction-cup dart gun at the screen. Here are the results. 64 percent of the subjects indicated the decision to fire at the lone individual in scene one, even though he could have simply been target-shooting. In scene two with clutter but no other people, 67 percent fired. Scene three added the “victim” and bystanders, and the firing rate rose to 88 percent. Finally, in scene four when the firearm was replaced with the power screwdriver, the firing rate remained high at 85 percent. Significantly, more than eight out of ten study respondents failed to distinguish an innocuous tool from a weapon. But, what does the average citizen expect from an officer in these cases? That was determined by experiment number two.

Once again, the researchers crafted scenes that were digitally photographed. In this case, they consulted with highly-experienced officers from the Fresno Police Department. They wanted to construct a scene that demonstrated a lethal threat to a victim that any officer would classify as clearly needing the intervention of deadly force in order to defend the life of the victim. In this scene, the subject is portrayed as clearly threatening the victim with a handgun (a Beretta 9mm). As in experiment one, the environment is well lit, but in this case the study participants were provided a full five seconds to view the scene. After viewing the scene, the subjects were asked what they believe an officer should do upon encountering the situation depicted. They were also asked to provide reasons for their responses. Here are the results of experiment two. Are you sitting down?

Nine out of ten of the respondents were of the opinion that an officer should hold his fire in this situation (remember experiment number one where over eight out of ten shot a subject holding a power screwdriver?) When asked why an officer should not shoot, the following explanations were provided:

• The daylight and public conditions would preclude the perpetrator’s firing
• The officer should fire only if the perpetrator fired first
• The officer should verbally convince the perpetrator to drop the weapon
• If the perpetrator had already murdered someone then the officer could shoot
• The suspect “did not look like she wanted to kill”

These are the potential jury members sitting in judgment when an officer is sued or tried for any force encounter in which he may be involved. This demonstrates why it is critical that law enforcement force-experts possess the ability to fluently educate the public and sometimes even our own investigators as to the human dimensions involved in critical incidents. Doctor Sharps’ book is a tremendous resource to those taking on this challenge.

An Important Book for Tactical Trainers
Dr. Sharps writes with great wit while providing scientific details that the lay person can easily understand. While every officer can obtain great value from this book, I looked at it from a trainer’s perspective and can say that it is the most important book I have yet read for tactical trainers. Using his knowledge of cognitive psychology, the results of his studies, and cognitive and psychological post-mortems of real events including Custer’s last stand, the Battle of Mogadishu, and the Battle of the Bulge, Dr. Sharps provides profound insight into human cognition, memory, and decision-making when under the duress of stressful events.

Dr. Sharps discusses the evolution of the human brain and how much of its automatic processing while under life-endangering stress still responds as if in another era: “Much of the brain that developed during the sabertooth age is still with us in the age of methamphetamine, and part of it is not very accessible to conscious awareness.” He details the byproducts of acute stress including sound anomalies, tunnel vision, time distortions, memory loss, intrusive thoughts, and dissociation and paralysis and why these perceptual distortions occur. But, most importantly he informs the reader of his “Gestalt/Feature Intensive” (G/FI) processing theory. This is where his book takes a turn from most others with similar themes as he demonstrates a solution to the human performance limitations encountered during critical events.

The human brain processes information in two ways, gestalt and feature intensive. They are not distinct or separate entities but rather lie on a continuum. However, the brain defaults to a pattern-recognition mode of processing, especially when time is of the essence. In order to access the gestalt patterns in memory, these mental blueprints must first have been encoded into long-term memory. That is accomplished with feature-intensive training and practice.

Good tactical decisions can only be made if training is front-loaded, explicit, and feature intensive. Evidence suggests that the cavalry soldiers at Little Big Horn tried to use small mounds of soft soil as positions of cover. One might say that this was simply a “stupid” response. However, when it comes to life-endangering circumstances, our brains under that level of stress are not real smart. This is more of a training lapse than an intelligence lapse. Imagine if the soldiers had received explicit, front-loaded, terrain-specific, feature-intensive training: “The Great Plains provide few points of natural cover. You may have a tendency to hide behind something like a prairie dog mound, or a rotten log or something, but it won’t work. If you have to retreat, keep riding erratically until your reach an arroyo, or a big rock, or something really substantial behind which to take cover.”

If the soldiers then practiced their maneuvers in an environment with terrain features similar to the actual battlefield, the likelihood of tactical blunders may have been reduced.

Dr. Sharps continues his G/FI theme as he addresses “command psychology” and how that applies to both strategic and tactical decisions. Mind-sets and cognitive dissonance, if allowed to control rather than inform a commander’s decision-making, can lead to catastrophic consequences. He dissects both the “Black Hawk Down” event and the actions of commanders during the Battle of the Bulge from a human cognition perspective in order to demonstrate both productive and unproductive decisions. He is acutely aware that lives hang in the balance based upon the decisions that the human brain makes when it is processing under pressure.

For decades other industries such as NASA, the Air Force and the Navy, civil aviation, the nuclear industry, the medical field, and even wild-land firefighting have researched and applied the science of human factors in order to better train, prepare, and protect their personnel. It is only comparatively recently that the law enforcement profession has come to embrace and apply this science to force encounters and decision making. It is incumbent upon trainers, investigators, and litigators to develop their understanding of how the human dimensions affect the performance of police officers when faced with tense, split-second, and rapidly evolving situations, and Dr. Sharps’ book is an excellent starting point. Should the reader wish to delve more deeply into human factors research, feel free to contact me at and I will gladly share my reading list of almost 40 books and CD’s that I have found highly instructive.

Steve “Pappy” Papenfuhs is the CEO of Battalion Defense which distributes premier armor, armor carriers, ballistic helmets and shields, and other tactical kit. Pappy retired as a sergeant after serving 29 years with the San Jose, California Police Department. During his career he worked Patrol, Field Training (FTO), Street Crimes, SWAT, Auto Theft, Sexual Assaults, Narcotics, Family Violence, and supervised the department’s in-service Training Division. He holds a Force Analysis certification from the Force Science Research Center, and is a certified instructor with the California Commission on Peace Officers Standards and Training (POST) in several disciplines including: Firearms, Defensive Tactics, Baton, Force Options, and Emergency Vehicle Operations (EVOC). In addition to running Battalion Defense and teaching both academy recruits and in-service officers, Pappy provides expert witness consultation in police practices, use of force, and training issues.

Contact Steve Papenfuhs.