Final answer:
The underlying assumption of abnormal child behavior is that it can be influenced by a variety of factors, including genetics, environment, and personal experiences. Behavior is not solely determined by any single factor, but rather by the complex interaction of multiple elements.
Step-by-step explanation:
The underlying assumption of abnormal child behavior is D. Abnormal behavior can be influenced by multiple factors. Psychological theories and research have highlighted that abnormal behavior, or variations in mental health and psychological patterns, often involve a complex interplay between genetic, environmental, biological, and situational elements. For instance, the behavioral perspective in psychology, notably associated with B. F. Skinner, emphasizes the role of environmental influences and reinforcement in shaping individual behavior, countering the idea of biological determinism. Furthermore, contemporary psychologists recognize that while temperament may have a biological basis, environmental interactions and maturation also play a critical role in how children's personalities unfold (Rothbart, 2011; Thomas and Chess, 1977).
Consequently, when considering child behavior, it's generally understood that neither genetic predisposition nor environmental factors alone are responsible for abnormal behaviors. Instead, behavior is influenced by a multilayered set of factors, including genetics, upbringing, cultural context, and individual experiences. This viewpoint is corroborated by research on conditions such as neurodevelopmental disorders, where it's recognized that a multitude of genes and environmental triggers can interact in complex ways to influence the development of these conditions.