confidence in their ability to control stressful situations and, therefore, are
less likely to suffer the health-harming consequences of stress (Weinstein &Quigley, 2006). A study of business executives in high-stress positions found
that internals were less likely to become ill than externals (Kobasa, 1979).
Internals also are more likely than externals to seek out information about
health problems (Wallston, Maides, & Wallston, 1976). However, as with psy-
chotherapy success, a match between locus of control and the health message
may be the most effective approach. One study looked at the effectiveness of cam-paigns encouraging middle-aged women to obtain a mammogram (Williams-
Piehota, Schneider, Pizarro, Mowad, & Salovey, 2004). Half the women received
a brochure and phone call that was targeted to internals. The brochure was titled“The Best Thing YouCan Do for Your Health, ”and contained messages like,
“You hold the key to your health. ”The other half received messages targeted to
externals. The brochure was titled, “The Best Thing Medical Science Has to
Offer for Your Health, ”with messages like, “Health care providers hold the key
to your health. ”As shown in Figure 14.9, internal women were more likely to
get a mammogram within the next 6 months when they received the internally
worded messages. In contrast, external women were more likely to get a mammo-
gram when receiving the externally oriented message.
Although researchers often find a connection between locus of control
and health, this is not always the case. Some investigations fail to find health dif-ferences between internals and externals or find only weak effects (Bettencourt,
Talley, Molix, Schlegel, & Westgate, 2008; Norman & Bennett, 1996). Why
might this be so? To answer this question, we need to return to Rotter ’st h e o r y .
Recall that Rotter said behavior was a function of both expectancy andrein-
forcement value. That is, I might expect that studying for a test will result in agood grade. However, if I don ’t value that grade, I am still unlikely to make
the effort.
Psychologists make similar predictions when they apply Rotter ’s model to
health behaviors (Wallston, 1992; Wallston & Smith, 1994). That is, believ-
ing that your actions can affect your health is not enough. You also need to
55
50
45
3540
30Percentage Obtaining 
MammogramsInternals
Externals
Internal
MessageExternal
Message
FIGURE 14.9 Percentage of Women Obtaining Mammograms
Source: Adapted from Williams-Piehota et al. (2004).Locus of Control 407