ABSTRACT
The research in psychology is based on the fiction that individual differences are noise in the data that interfere with the greater goal of describing human performance. Human behavior, in contrast, unfolds in a social context shaped by language, politics, and many other dimensions. These environmental features matter deeply for human behavior, but just as the individual difference variables that define, they too are largely ignored in psychological research. One way in which psychology is moving away from these models is by examining how intense experience modifies cognitive performance and brain structure. The research, bilingualism has been found to lead to enhanced executive functioning across the life span, although often in conjunction with poorer verbal processing than monolinguals, and contribute to "cognitive reserve" that protects against cognitive decline in both healthy aging and dementia. Behavioral evidence for superior performance of bilinguals compared to monolinguals in nonverbal executive control tasks has been shown across the life span.
