[From Force Science
News provided by The Force Science Research Center.]
Force Science News #70
April 20, 2007
Note: We’d like to hear your reaction to the
observations and proposals made by Trainer Tom Aveni in the report
below. Please e-mail Force Science News.
Does your agency encourage you to nap on duty?
Probably not. But your department might get better performance and you
might be safer if regulated snoozing was permitted, according to
well-known trainer and consultant Tom Aveni, head of the Police
Policy Studies Council and a Technical Advisory Board member of the Force
Science Research Center at Minnesota State University-Mankato.
Recent research reports offer some impressive support for Aveni’s
unconventional position by documenting the health and judgment benefits
of limited workplace dozing.
“Most of the egregious errors committed in law enforcement occur when
officers are fatigued or dealing with low-light conditions,” Aveni
pointed out in a presentation on “Surviving the Night Shift” at a
conference of the International Law Enforcement Educators and Trainers
Assn. (ILEETA). And the rotating, irregular, or extended shifts common
in policing contribute significantly to officer fatigue, he declared.
“Those working rotating shifts, for example, average 5.5 hours of sleep
when working night hours,” Aveni said. Because of second jobs, family
obligations, or disrupted sleep patterns, some officers, at least on
occasion, come to work with as little as 3 hours’ sleep, “resulting in
the same level of impaired performance as ingesting the legal limit of
“Sleep deficits may be partly recouped on days off,” but until a full
and satisfying compensation occurs an officer’s “mood and performance
are routinely affected.”
Given the slim, real-world probability of consistently getting
sufficient sleep, naps during duty hours could help officers fight
dangerous fatigue, Aveni argues, along with brief exercise breaks,
proper caffeine intake, low glycemic (sugary) food consumption, and
exposure whenever possible to brightly lighted areas.
“Napping is usually seen as being derelict of duty, but progressive
agencies really should encourage it. It’s a healthy means of fighting
fatigue, and a short nap--20 to 30 minutes--can work wonders in
increasing alertness and judgment.”
Recent research studies tend to agree.
For instance, a 6-person research team at Stanford University, headed by
Dr. Rebecca Smith-Coggins, studied the effects of napping on 49 resident
physicians and nurses working nights (1930-0730) in a university trauma
center ER. Some were allowed to take up to a 40-min. nap at 0300, while
a control group stayed awake for the entire 12-hr. shift.
Napping was done in a dark, quiet room away from ER activities, with a
bed and linens provided. Ninety percent of the nap subjects, whose mean
age was 30, were able to fall asleep quickly (within 11 minutes) and
slept for an average of nearly 25 minutes.
Before and after the shift and also after the nap period, both groups
were tested for vigilance, memory, mood, and task performance. After
shift, all subjects participated in a 40-min. driving simulation test to
measure “behavioral signs of sleepiness and driving accuracy.”
At the end of shift, the nap subjects showed quicker reaction times and
fewer lapses in vigilance, according to the study. They reported “more
vigor, less fatigue, and less sleepiness” than those who had worked
without napping. Moreover, the nappers were able to more quickly
complete a simple job-performance task (the simulated insertion of a
catheter IV) and exhibited “less dangerous driving,” although both
groups showed signs of driving impairment after working overnight.
The only negative outcome evident in the nappers was a temporary
worsening of memory “immediately after the nap.” This was attributed to
sleep inertia, “the feeling of grogginess…that can persist for up to 30
minutes after awakening.”
Generally, “nap intervention provided beneficial effects,” the
researchers noted, and planned naps in the workplace might well “promote
a high level of alertness, attention to detail, and decision-making
[A full report of this study appears in the Nov. 2006 issue of the
Annals of Emergency Medicine, under the title “Improving Alertness and
Performance in Emergency Dept. Physicians and Nurses: the Use of Planned
Naps.” Read a summary.]
Aveni speculates that some officers’ moral judgment may also be improved
by fatigue relief in the form of napping. Certainly the findings of
another recent study suggest that morally framed decision-making can be
negatively impacted by extended fatigue, which tends to affect activity
in the region of the brain that plays a major role in moral reasoning.
In this study, Dr. William Killgore and colleagues at the Walter Reed
Army Institute of Research tested 26 healthy, active-duty military
personnel after 2 sleepless nights to see whether the lack of shut-eye
would hinder their ability to make decisions in the face of emotionally
charged, moral dilemmas. “The findings could have implications for
people who are both routinely sleep-deprived and often need to make
quick decisions in a crisis,” the researchers said. That would include
soldiers in combat and cops on the street.
The participants were first tested after an adequate sleep period and
again after an unusually long stint (53.5 hours) of continuous
wakefulness. They were given a wide variety of decision-making
scenarios, including some that were highly emotionally charged, highly
personal, and burdened with moral considerations.
For example, one scenario stated: “You are negotiating with a powerful
and determined terrorist who is about to set off a bomb in a crowded
area.” Thousands of people would be killed by the detonation. Your one
advantage is that you have his teen-age son in your custody. [The] only
one thing you can do to stop him from detonating his bomb [is to] break
one of his son’s arms” in front of a camera “and then threaten to break
the other one if he does not give himself up.” The participants were
asked: “Is it appropriate for you to break the terrorist’s son’s arm?”
[All other scenarios used are described here.]
The researchers were not concerned with evaluating “right” or “wrong”
answers—only with analyzing the decision-making process. Among other
things they found that:
--the test participants took significantly longer to decide how to react
to the highly personal, morally charged situations when they were
sleep-deprived compared to when they were well rested. This suggests
that fatigue “has a particularly debilitating effect on judgment and
decision-making processes that depend heavily upon the integration of
emotion with cognition,” the researchers concluded.
--sleep loss also led generally “to an increase in the permissiveness or
tolerance for judging difficult courses of action as appropriate,” the
study found. Only participants with above-average “emotional
intelligence,” the ability to empathize and interact socially with other
people, showed resistance to being influenced by sleeplessness in this
Such findings “may have implications for those in occupations”
frequently associated with sleep loss “and in which real-world moral
dilemmas may be encountered…. When sleep deprived, such personnel may
experience greater difficulty reaching morally based decisions under
emotionally evocative circumstances and may be prone to choosing courses
of action that differ from those that they would have chosen in a fully
rested state,” the study report states.
“The implications for police work, where life-and-death decisions must
often be made in crisis mode, is obvious,” Aveni recently told Force
[A full report of this study can be found in the journal Sleep, vol. 30,
#3, 2007, under the title: “The Effects of 53 Hours of Sleep Deprivation
on Moral Judgment.” Read the abstract.]
A third recent study concerned an important health benefit of napping.
A team of Greek and American researchers, headed by Dr. Androniki Naska
of the University of Athens Medical School, confirmed that people who
take at least 3 naps a week lasting 30 minutes or longer cut their risk
of dying from a heart attack by 37 percent.
The study followed more than 23,600 originally healthy men and women for
more than 6 years. Even those who napped only occasionally had a 12 per
cent lower coronary mortality rate than those who never napped. Men who
were working seemed especially to benefit.
Napping, the researchers said, appeared to reduce stress, and “there is
considerable evidence that both acute and chronic stress are related to
[A full report of this study appeared in Archives of Internal Medicine
on Feb. 12, 2007, under the title “Siesta in Healthy Adults and Coronary
Mortality in the General Population.” Read a summary]
“Police agencies need to start looking at napping as a restorative,
preventive measure, as something that can prevent serious errors,” Aveni
“Other measures for fighting fatigue tend to be transitory. Rolling your
squad car window for a blast of cold, fresh air may perk you up for 2 to
3 minutes. Taking an exercise break where you do jumping jacks may buy
you a half hour’s benefit. But with a nap of at least 20 minutes, you’ll
see a pronounced improvement in performance, in vigilance, in eye-hand
coordination that can last up to 4 hours.
“Officers forced to work rotating shifts are thrust into an unnatural
work environment. In many cases, your body never adjusts to the changes
in schedule. Agencies need to consider effective countermeasures for
Most agencies would understandably want to control where any officially
sanctioned napping takes place, Aveni acknowledges. Inside a patrol car
is not recommended, not only because of public perception but also
because of discomfort, distractions, and safety.
A sound-insulated area with recliners or cots inside a police facility
is more desirable, with naps scheduled in advance or permitted on
request. Time should be allowed, he says, to counteract sleep inertia
upon awakening with mild exercise before heading back on patrol.
Napping could become a collective bargaining issue in the future, Aveni
believes. But today, he admits, he knows of no department with an
official pro-napping policy.
The precedent is there, however, in industries like trucking,
railroading, and aviation. A New York company called MetroNaps has
started marketing customized napping “pods”--7-ft.-long, hooded
recliners with headphones, temperature controls, and lights that dim--to
corporations willing to be on the cutting edge of a new trend.
Reflecting on other hazardous occupations where “preventive napping” has
become part of the culture, Aveni notes: “If we held law enforcement to
civilian standards, this would be a very different profession.”
[Remember: We’d like to hear your reactions to the Aveni’s observations
and proposals. E-mail them now.]
The FSRC was launched in 2004 by Executive
Director Bill Lewinski, PhD. -- a specialist in police psychology -- to
conduct unique lethal-force experiments. The non-profit FSRC, based at
Minnesota State University-Mankato, uses sophisticated time-and-motion
measurements to document-for the first time-critical hidden truths about
the physical and mental dynamics of life-threatening events,
particularly officer-involved shootings. Its startling findings
profoundly impact on officer training and safety and on the public's
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