Final answer:
Studies from the 1940s onward have indicated that intelligence is multifaceted, influenced by environmental, cultural, and socioeconomic factors, rather than being determined solely by genetic predisposition. Controversies such as those sparked by Arthur Jensen's work have led to a broader understanding that intelligence is complex and cannot be reduced to simple racial categorizations.
Step-by-step explanation:
By the 1940s, psychologists like Klineberg became proponents of the idea that observed racial differences in intelligence could be better explained by factors such as environmental influences, cultural background, and socioeconomic status rather than genetic predisposition. This view was supported by evidence presented in various studies, which indicated that intelligence is not solely determined by genetic factors, but is also significantly shaped by the environment in which an individual is raised. The long-held belief that a racial group's lower IQ could be attributed to genetics has been increasingly challenged, especially as shifting educational and socioeconomic landscapes have led to the narrowing of IQ gaps across racial groups.
Further research throughout history, including the controversial work of Arthur Jensen and the refuting studies that followed, has shown that intelligence is a complex trait influenced by multiple factors. Environmental stressors, such as living in poverty, can have profound effects on brain development and function, thereby impacting individual IQ levels. This underscores that many elements, spanning from genetic components to educational opportunities and beyond, collectively shape an individual's intelligence.