Why do traits come together? The underlying trait and network approaches

This chapter deals with one of the most pervasive personality-related phenomenon: the coalescence of tendencies for specific thoughts, feelings and behaviors (characteristics) into broader patterns—traits. Two possible explanations are discussed. The more established explanation is that certain characteristics tend to co-exist because they reflect a common underlying cause. A more recent explanation is that they may also hang together because of having direct causal links between them—some characteristics can contribute to, or inhibit, others. However, the chapter offers a more general, mathematically formalized framework, which can, in fact, merge the to explanations. Furthermore, this framework can be used to represent both processes within individuals and individual differences, with the latter emerging from the former. This means potential for a formal bridge between two branches of personality psychology—the social cognitive and trait approaches. Some empirical findings will be reviewed that are consistent with the proposed framework.