individual's belief in their capacity to execute behaviors necessary to produce specific performance attainments. It is a related concept introduced by Albert Bandura, and has been measured by means of a psychometric scale. It differs from locus of control by relating to competence in circumscribed situations and activities (rather than more general cross-situational beliefs about control). Bandura has also emphasised differences between self-efficacy and self-esteem, using examples where low self-efficacy (for instance, in ballroom dancing) are unlikely to result in low self-esteem because competence in that domain is not very important (see valence) to an individual. Although individuals may have a high internal health locus of control and feel in control of their own health, they may not feel efficacious in performing a specific treatment regimen that is essential to maintaining their own health. Self-efficacy plays an important role in one's health because when people feel that they have self-efficacy over their health conditions, the effects of their health becomes less of a stressor. Smith (1989) has argued that locus of control only weakly measures self-efficacy; "only a subset of items refer directly to the subject's capabilities". Smith noted that training in coping skills led to increases in self-efficacy, but did not affect locus of control as measured by Rotter's 1966 scale. Stress The previous section showed how self-efficacy can be related to a person's locus of control, and stress also has a relationship in these areas. Self-efficacy can be something that people use to deal with the stress that they are faced within their everyday lives. Some findings suggest that higher levels of external locus of control combined with lower levels self-efficacy are related to higher illness-related psychological distress. People who report a more external locus of control also report more concurrent and future stressful experiences and higher levels of psychological and physical problems. These people are also more vulnerable to external influences and as a result, they become more responsive to stress. Veterans of the military forces who have spinal cord injuries and post-traumatic stress are a good group to look at in regard to locus of control and stress. Aging shows to be a very important factor that can be related to the severity of the symptoms of PTSD experienced by patients following the trauma of war. Research suggests that patients with a spinal cord injury benefit from knowing that they have control over their health problems