Page 106 - Journal of Special Operations Medicine - Spring 2017

the time it takes others to tackle just one. Hence, it may to appreciate how assuming that average applies to any-
seem self-evident, and, therefore, somewhat trivial, to one can result in erroneous conclusions when data are
note that people differ in terms of performance aptitudes analyzed based on that assumption. In some cases, the
and how they may respond to different interventions or focus on group means can lead to the opposite conclu-
training. Thus, individual differences might define what sion of what the individual data are actually showing
“optimal performance” means for any given person. Ac- about different responses and their variability. Figure 1
cording to Kondraske’s General Systems Performance presents real-life data on how inaccuracies can emerge
9
Theory, every task requires a minimal level of various from looking at just group means in a study. One con-
5
resources (e.g., strength, aerobic capacity, reaction time, clusion from the Figure 1A could be that exercise in-
information processing speed and/or short-term memory duced a marked response in substance X, but looking
capacity) and it is the totality of these resources that al- at individual data suggests otherwise: Some individuals
lows missions to be performed successfully. Everyone has have marked responses and others barely respond at all.
different resource capacities; yet, understanding which In Figure 1B, a treatment was provided and the mean
resource differences matter most for making actionable suggests the treatment caused an effect, whereas indi-
recommendations or drawing accurate conclusions about vidual data indicate a large effect in some and no, or
the best HPO approaches could mean the difference be- minimal, effect in others. Erroneous conclusions, and
tween operating as usual and developing and sustain- even recommendations, could easily have been drawn if
ing true competitive advantage. Understandably, then, only the means had been examined.
substantive debates about which individual differences
to tackle, and how to tackle them, are ongoing. Indeed, Figure 1 How just looking at means can result in erroneous
conclusion.
for many areas of research, the challenges of individual
differences remain highly relevant because failing to ac-
count for such variability can significantly impact the
reliability and reproducibility of certain scientific studies
and call into question some of the foundational conclu-
sions regarding what we think we know about human
psychology, social behavior, and health. This, no doubt,
has contributed to the “crises of reproducibility,” which
are increasingly being identified across disciplines, like
social psychology, economics, healthcare, and biomedi-
cine. (For further discussion on challenges to reproduc-
6
ible research that are relevant for HPO and P2, a special
issue of Nature details several and can be found at http://
www.nature.com/news/reproducibility-1.17552.)

Traditionally we have drawn actionable recommenda-
tions from group averages and means—for example, the
average response to a training intervention, the aver-
age time to accomplish a task, the average requirement (A) Stress hormone response to exercise: the means show a robust re-
for sleep, hydration, or micro- or macronutrients. This sponse but individual data point show huge variability. (B) The mean
does not imply, of course, that in the past we were com- of the stress hormone after exercise in response to a treatment suggests
mitting any research or scientific sins but only that our a small increase, but individual data show that some have a marked
response and others exhibit no response at all. Pre, before exercise;
9
tools, data, and models largely limited us to these ap- post, after exercise.
proaches. The traditional research design is entirely ap-
propriate for asking questions about large numbers of In the next section, we explore several HPO-relevant ar-
people (the key being the need to have large numbers of eas where we are beginning to appreciate the substantive
people in the studies in question); however, as a result, impact individual differences can have on our under-
individualized recommendations often cannot be made standing and application of strategies to help optimize
with any confidence. Now, in an age of new efforts to the performance of Special Operations Forces (SOF),
develop precision medicine and performance, we are re- and that further signal the need to move toward P2.
alizing that those seeking to truly optimize performance
must try to escape the “tyranny of the mean,” where Individual Nutritional Differences
7,8
averages can be counterproductive or unhelpful.
There are strong reasons to believe that, on average,
Importantly, because we know the “average” human certain general nutrition recommendations are likely to
does not refer to any actual person, we are beginning benefit most people and HPO approaches. However, a
7,8

82 Journal of Special Operations Medicine Volume 17, Edition 1/Spring 2017