第11章パーソナリティ

Bandura (1977, 1995) has studied a number of cognitive and personal factors that affect learning and personality development, and most recently has focused on the concept of self-efficacy. Self-efficacy is our level of confidence in our own abilities, developed through our social experiences. Self-efficacy affects how we approach challenges and reach goals. In observational learning, self-efficacy is a cognitive factor that affects which behaviors we choose to imitate as well as our success in performing those behaviors.

People who have high self-efficacy believe that their goals are within reach, have a positive view of challenges seeing them as tasks to be mastered, develop a deep interest in and strong commitment to the activities in which they are involved, and quickly recover from setbacks. Conversely, people with low self-efficacy avoid challenging tasks because they doubt their ability to be successful, tend to focus on failure and negative outcomes, and lose confidence in their abilities if they experience setbacks. Feelings of self-efficacy can be specific to certain situations. For instance, a student might feel confident in her ability in English class but much less so in math class.

Julian Rotter (1966) proposed the concept of locus of control, another cognitive factor that affects learning and personality development. Distinct from self-efficacy, which involves our belief in our own abilities, locus of control refers to our beliefs about the power we have over our lives. In Rotter’s view, people possess either an internal or an external locus of control (Figure 11.11). Those of us with an internal locus of control (“internals”) tend to believe that most of our outcomes are the direct result of our efforts. Those of us with an external locus of control (“externals”) tend to believe that our outcomes are outside of our control. Externals see their lives as being controlled by other people, luck, or chance. For example, say you didn’t spend much time studying for your psychology test and went out to dinner with friends instead. When you receive your test score, you see that you earned a D. If you possess an internal locus of control, you would most likely admit that you got a D because you didn’t spend enough time studying and decide to study more for the next test. On the other hand, if you possess an external locus of control, you might conclude that the test was too hard and not bother studying for the next test, because you figure you will get a bad grade anyway. Researchers have found that people with an internal locus of control perform better academically, achieve more in their careers, are more independent, are healthier, are better able to cope, and are less depressed than people who have an external locus of control (Benassi, Sweeney, & Durfour, 1988; Lefcourt, 1982; Maltby, Day, & Macaskill, 2007; Whyte, 1977, 1978, 1980).

Walter Mischel was a student of Julian Rotter and taught for years at Stanford, where he was a colleague of Albert Bandura. Mischel surveyed several decades of empirical psychological literature regarding trait prediction of behavior, and his conclusion shook the foundations of personality psychology. Mischel found that the data did not support the central principle of the field—that a person’s personality traits are consistent across situations. His report triggered a decades-long period of self-examination, known as the person-situation debate, among personality psychologists.

Mischel suggested that perhaps we were looking for consistency in the wrong places. He found that although behavior was inconsistent across different situations, it was much more consistent within situations—so that a person’s behavior in one situation would likely be repeated in a similar one. And as you will see next regarding his famous “marshmallow test,” Mischel also found that behavior is consistent in equivalent situations across time.

One of Mischel’s most notable contributions to personality psychology was his ideas on self-regulation. According to Lecci & Magnavita (2013), “Self-regulation is the process of identifying a goal or set of goals and, in pursuing these goals, using both internal (e.g., thoughts and affect) and external (e.g., responses of anything or anyone in the environment) feedback to maximize goal attainment” (p. 6.3). Self-regulation is also known as will power. When we talk about will power, we tend to think of it as the ability to delay gratification. For example, Bettina’s teenage son made strawberry cupcakes, and they looked delicious. However, Bettina forfeited the pleasure of eating one, because she is training for a 5K race and wants to be fit and do well in the race. Would you be able to resist getting a small reward now in order to get a larger reward later? This is the question Mischel investigated in his now-classic marshmallow test.

Mischel designed a study to assess self-regulation in young children. In the marshmallow study, Mischel and his colleagues placed a preschool child in a room with one marshmallow on the table. The children were told they could either eat the marshmallow now, or wait until the researcher returned to the room, and then they could have two marshmallows (Mischel, Ebbesen & Raskoff, 1972). This was repeated with hundreds of preschoolers. What Mischel and his team found was that young children differ in their degree of self-control. Mischel and his colleagues continued to follow this group of preschoolers through high school, and what do you think they discovered? The children who had more self-control in preschool (the ones who waited for the bigger reward) were more successful in high school. They had higher SAT scores, had positive peer relationships, and were less likely to have substance abuse issues; as adults, they also had more stable marriages (Mischel, Shoda, & Rodriguez, 1989; Mischel et al., 2010). On the other hand, those children who had poor self-control in preschool (the ones who grabbed the one marshmallow) were not as successful in high school, and they were found to have academic and behavioral problems. A more recent study using a larger and more representative sample found associations between early delay of gratification (Watts, Duncan, & Quan, 2018) and measures of achievement in adolescence. However, researchers also found that the associations were not as strong as those reported during Mischel's initial experiment and were quite sensitive to situational factors such as early measures of cognitive capacity, family background, and home environment. This research suggests that consideration of situational factors is important to better understand behavior.

Today, the debate is mostly resolved, and most psychologists consider both the situation and personal factors in understanding behavior. For Mischel (1993), people are situation processors. The children in the marshmallow test each processed, or interpreted, the rewards structure of that situation in their own way. Mischel’s approach to personality stresses the importance of both the situation and the way the person perceives the situation. Instead of behavior being determined by the situation, people use cognitive processes to interpret the situation and then behave in accordance with that interpretation.