Page 145 - Biobehavioral Resilence to Stress

122 Biobehavioral Resilience to Stress

reported by Waugh, Wager et al. (2007) suggest that when faced with uncer-
tainty, low-resilient individuals tend to expect the worst outcome and experi-
ence physiological responses accordingly.

Controllability
The second important consideration in anticipation of stress is perceived

control of outcome. A high level of confidence may support a sense of con-

trol and thus affect emotional response during anticipation of stress. In a
meta-analysis of the relationship between acute psychological stress and
cortisol, a hormone associated with preparing the body for stress, Dickerson
and Kemeny (2004) found that for tasks requiring motivated performance,
low-controllability tasks were associated with the most consistent and per-

sistent cortisol responses. An effect of cortisol is its tendency to depress the
body’s immune system, which allows metabolic redirection to vital organs.

Th is effect is adaptive in the short term, but chronically high levels of corti-
sol can lead to chronic immune depression and resulting deleterious health
defects (Sapolsky, Romero & Munck, 2000). Therefore, chronic low perceived

controllability may have serious implications for long-term coping and
health (Dickerson & Kemeny, 2004).
Some researchers have also found that cardiovascular reactivity varies
with the level of perceived control. In some studies of perceived control and
cardiovascular reactivity, high levels of perceived control have been associ-
ated with increases in cardiovascular reactivity (Bongard, 1995; Manuck,
Harvey, Lechleiter & Neal, 1978). However, experimental tasks in these

studies tend to confound effort and control, and so observed effects on car-
diovascular reactivity may not have been related to perceived controllabil-
ity, but rather to level of effort in the attempt to avoid aversive stimulation

(Obrist, Webb, Sutterer & Howard, 1970). Other studies have shown that

when the level of effort is kept constant across all task conditions, higher
perceived control is associated with decreased cardiovascular reactivity
(Gerin, Litt, Deich & Pickering, 1995; Gerin, Pieper, Marchese & Pickering,
1992; Weinstein, Quigley & Mordkoff, 2002). A possible explanation for this

effect is that perceived control supports adequate cardiovascular reactivity to

engage in the task but not so much as to hinder task performance. Eff ects of
this type are consistent with the well-documented “inverted U-curve” rela-
tionship between arousal and performance (Yerkes & Dodson, 1908).
Physiological responses to anticipation and stress can be related spe-

cifically to emotional experience and resilience. A recent study by Lerner,
Gonzalez, Dahl, Hariri, and Taylor (2005) attempted to disentangle the
influences of various specific emotional experiences and personality vari-

ables on cortisol and cardiovascular reactivity. Participants performed
stressful tasks (e.g., counting backward while being urged to go faster by the

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