It’s been a widely held belief that a police officer’s heart rate has a direct impact on how he reacts in stressful situations. The consensus has been that as the heart rate increases, fine motor skills decrease, thus limiting our ability to react swiftly and appropriately. That theory, however, has had its share of detractors who dispute the findings and question the validity of the testing. Recently, research results have been published that not only challenge those long-held beliefs, but also debunk the position that heart rate is a reliable predictor of police officer performance.
The results of the surprising new research dealt with three specific areas of physiological arousal: officers’ verbal communication; nonverbal communication; and, tactical skills. The study, published April 2019 in Frontiers in Psychology, Differential Effects of Physiological Arousal Following Acute Stress on Police Officer Performance in a Simulated Critical Incident, found that heart rates are not a totally reliable predictor of officer performance. Please read on.
For years, law enforcement trainers have been studying the correlation between elevated heart rates and performance during stressful encounters and situations. Much of the research included the wearing of heart rate monitors that recorded base line heart rates and rates recorded during the confrontations. The results were predictable—those participants’ heart rates were much higher during the encounter than before. Logical, right? But what did those findings prove? Particularly when many of those involved in the training successfully resolved the situation they confronted, even with elevated heart rates.
The Protocol
A snapshot of the recent FIP study shows that a group of officers volunteered to participate in reality-based training involving a scenario resulting in a deadly force situation. The officers were given non-lethal training ammo and had their levels of cortisol, antithrombin, and heart rate measured both before and after the scenario. Cortisol is a hormone which is mainly released at times of stress. When released into the bloodstream, it can act on many different parts of the body and can help the body respond to stress or danger, control blood pressure, and increase the body’s metabolism of glucose. Antithrombin is a protein in our blood stream which functions as a naturally occurring mild blood thinner that protects the body’s blood from clotting too much.
The researchers focused on measuring the involved officers’ performance in three areas: tactical skills; decision making; and, verbal and non-verbal communication. The officers were thrust into a simulation that involved multiple calls, dynamic environments, and surprise threats—an enactment of an actual event that resulted in a police officer’s death. Throughout the situation, the officers had their heart rates monitored. Circulating levels of cortisol and antithrombin were taken before and after the incident.
The Results
The reality-based training, as expected, did increase the officers’ arousal as evidenced by their increased heart rates. However, elevated heart rates were not the sole predictor of differences in performance. While changes in cortisol levels were unrelated to the skill assessments, greater increases in antithrombin were associated with better general performance. The downside was a specific deficit in officers’ verbal communication compared with their tactical performance and nonverbal communication.
The researchers concluded, “Based upon the reviewed evidence, there is seemingly a paradox of police officer performance under stress – aspects of awareness and vigilance are bolstered, whereas behaviors that rely on complex cognitive processes, including communication, are disrupted and well-rehearsed, proceduralized skills are seemingly spared. All of these functions are relevant to police officer performance and decision-making ability during critical incidents directly have consequences to officer and public safety.”
While verbal communication is diminished during stressful confrontations, the ability to communicate non-verbally, e.g., hand signals, head movements, etc., and familiarity with one’s weapon systems and tactics, are extremely important skills that can mean the difference between success and failure. For trainers this new study is extremely important. The results reinforce the importance of repetitive training as a means of reinforcing skills with the entire weapon system. Being able to draw or holster a weapon, discarding a spent mag and reloading a weapon, all without needing to look at the gear and gun, becomes a split-second advantage or disadvantage if you take your eyes off the fight. Practicing entries, traffic stops, defensive tactics, etc., until they all become automatic, can mean the difference between life and death.
In this age of increased violence resulting in more police officer injuries and deaths, the mission of the trainer becomes even more important. Reality based training, repetitive firearm drills, tactical training, and defensive tactics must have a higher priority in order for police officers to survive the streets. I note that in some circles the current mindset is shifting from warrior to guardian. No matter—it’s semantics—our job remains to survive and get home to our families each day. Proper training from skilled and dedicated trainers will help us do just that.
Stay Safe, Brothers and Sisters!
John Wills
John M. Wills is a former Chicago police officer and retired FBI agent. He is a freelance writer and award-winning author in a variety of genres, including novels, short stories and poetry. John also writes book reviews for the New York Journal of Books, and is a member of the National Book Critics Circle. His new book, The Year Without Christmas, is available now. Visit John at: www.johnmwills.com.
