Traits are variables or dimensions which are continuous. According to the Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association, personality traits are prominent aspects of personality that are exhibited in a wide range of important social and personal contexts (Figure 1). In other words, individuals have certain characteristics (traits) which partly determine their behavior. Trait theories of psychology are theories derived by psychologists to categorize and explain personality through the use of these traits.
One strength of the trait perspective is its ability to categorize observable behaviors. Researchers have found that examining the aggregate behaviors of individuals provides a strong correlation with traits. In other words, observing the behaviors of an individual over time and in various circumstances provides evidence for the personality traits categorized in trait theories.
Another strength is that trait theory uses objective criteria for categorizing and measuring behavior. Along with this strength is the strength that trait theories were developed often independently of each other and using factor analysis to derive at a specific set of traits. Trait theorists, while developing their theories independent of each other, often arrived at a similar set of traits through factor analysis.
One criticism of the trait perspective lies in their predictive value. Critics argue that traits do a poor job of predicting behavior in every situation. Some psychologists argue that the situational variables (i.e., environmental factors) determine behavior, not traits; other psychologists argue that a combination of traits and situational variables influence behavior.
Another limitation of trait theory is that it requires personal observations or self-report to measure. Self-report measures require that an individual be introspective enough to understand his or her own behavior. Personal observations requires that an individual spend enough time observing someone else in a number of situations in order to be able to provide an accurate assessment of behaviors. Both of these measures are subject to observer bias and other forms of inaccuracy.
Another limitation, and criticism, of trait theory is that is does not explain why an individual behaves as he or she does. Trait theories provide information about people, and about which traits cause which behaviors, but there is no indication as to why these traits interact in the way that they do. For example, an extroverted individual is energized by social interactions and seeks out social situations, but trait theory does not offer any explanation for why this might occur or why the introvert would avoid such situations.