Synergistic and dynamic genotype-environment interplays in the development of personality differences

Abstract How can the development of individual differences in humans’ characteristic patterns of feeling, thinking, striving, and behaving be understood within a behavior genetic framework? How do genes and environments unfold and combine their influences? And how can the development of personality similarity and differences between twin siblings help us to get a sense for the complex interplay between genetic and environmental factors in shaping personality development? In this chapter, we introduce basic and advanced concepts of behavior genetics to elaborate answers to these questions. We combine old and new ideas to establish a basis for a new perspective on genetically informative personality psychology. An individual's personality is not only described as a passive product of their genetic makeup, cumulative life experiences, and trans- or interactions between them, but also as a mediating element of nature and nurture and thus as a driving and moderating part of its own development.