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Resilience and Survival in Extreme Environments 143

In some instances, survival in extreme conditions may be explained
by physiological reserve. For example, extreme energy deprivation can be
explained fairly simply in terms of body fat reserves, which serve to protect
against starvation and cold injury. For example, compared to their Indian
counterparts, larger and better fed British soldiers were better able to sur-
vive the Siege of Kut-al-Amara in 1915 (Hehir, 1922). Similarly, women were
more likely than men to survive the Siege of Stalingrad during World War II
(Brozek, Wells & Keys, 1946). Fat stores and perhaps also fat energy utiliza-
tion (Hoyt & Friedl, 2006) were probably key contributors to greater physical
“resilience” in each case. There are numerous considerations in nutritional sta-

tus (e.g., body fat/energy stores, antioxidant intake, iron and zinc balance, etc.)

that may exert an important or determinant influence on mental and physi-
cal performance in extreme environments (Committee on Military Nutri-
tion Research [CMNR], 2006).
Although psychological factors associated with survival are certainly

less well-defined, there is little doubt that psychological factors are essential
for survival in extreme environments. Several authors have proposed that
one important aspect or component of resilience is a personality trait known
as hardiness (King, King, Fairbank, Keane & Adams, 1998; Maddi, 1999).

Hardy individuals tend to view difficult situations as positive challenges,
and are guided by a strong sense of control and commitment (Kobasa, 1979).
Likewise, individuals who employ psychological strategies to maintain hope,
even in seemingly hopeless situations, appear more likely to survive in situ-
ations that involve psychological stress and energy deficit; these individu-

als seem to benefit by enhanced defense against infectious disease, as well

as improved recovery from injury and illness (Friedl, 2003). Th e long-term
consequences of extreme stress are more difficult to explain. For example,

POW camp survivors have an increased risk of developing neurodegen-
erative disease (Page & Tanner, 2000). Those who succumb to these health

consequences may reflect diminished resilience as a consequence of coping

behaviors, the damaging effects of specific nutritional deficiencies and other
stressors, or more susceptible genotypes.
For each anecdotal example of resilience to extreme environmen-
tal stress, there is a plausible mechanistic basis that expands upon general
stress mechanisms as originally described by Walter Cannon and Hans Selye

( Cannon, 1914; Selye, 1950). Clearly, the function and effects of the human
mind, brain, and body are complex and interactive, providing multiple
important opportunities and avenues to mediate human physiological and
psychological responses to extreme environments. By pursuing an improved
understanding of these mechanisms and their potential impact upon human
resilience, we can maximize opportunities for survival and sustained eff ec-
tive performance.

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