Читать книгу Lifespan Development - Tara L. Kuther - Страница 57

Perhaps the most fundamental question about lifespan human development concerns why people change in predictable ways over the course of their lifetimes. The answer reflects perhaps the oldest and most heated debate within the field of human development: the nature–nurture issue. Is development caused by nature or nurture? Explanations that rely on nature point to inborn genetic traits (heredity), maturational processes, and evolution as causes of developmental change. For example, most infants take their first steps at roughly the same age, suggesting a maturational trend that supports the role of nature in development (Payne & Isaacs, 2016). An alternative explanation for developmental change is nurture, the view that individuals are molded by the physical and social environment in which they are raised, including the home, school, workplace, neighborhood, and society. From this perspective, although most begin to walk at about the same time, environmental conditions can speed up or slow down the process. Infants who experience malnutrition may walk later than well-nourished infants, and those who are given practice making stepping or jumping movements may walk earlier (Siekerman et al., 2015; Worobey, 2014).

Although developmental scientists once attempted to determine whether development depended on nature or nurture, most now agree that both nature and nurture are important contributors (Rutter, 2014; Sasaki & Kim, 2017). Thus, walking is heavily influenced by maturation (nature), but experiences and environmental conditions can influence the timing of a child’s first steps (nurture). Today developmental scientists attempt to determine how nature and nurture interact and work together to influence how people grow and change throughout life (Bjorklund, 2018; Lickliter & Witherington, 2017).

To review, the three basic questions regarding lifespan human development are as follows:

1 Is developmental change gradual, showing continuity, or abrupt, illustrating discontinuity?

2 What role do people play in their own development—how much are they influenced by their surroundings and how much do they influence their surroundings?

3 To what extent is development a function of heredity, and to what extent is it a function of the environment in which individuals live?

Developmental scientists vary in their responses to these questions, as we will see throughout this book.