The Development and Diversity of Cognitive Flexibility: Greater Cultural Variation in Early Rule Switching than Word Learning

Cognitive flexibility, the adaptation of representations and responses to new task demands, improves dramatically in early childhood. It is unclear, however, whether flexibility is a coherent, unitary cognitive trait that develops similarly across populations, or is an emergent dimension of task-specific performance that varies across populations with culturally variable experiences. Children from two populations that differ in pre-formal education experiences completed two distinct tests of cognitive flexibility, matched for complexity. Three- to 5-year-old English-speaking U.S. children and Tswana-speaking South African children completed two language-processing cognitive flexibility tests: the FIM-Animates, a word-learning test, and the 3DCCS, a rule-switching test. U.S. and South African children did not differ in word-learning flexibility, showing similar age-related increases. In contrast, only U.S. preschoolers showed an age-related increase in rule-switching flexibility; South African children did not. Working memory explained additional variance in both tests, but did not modulate the interaction between population-sample and task. The data suggest that rule-switching flexibility may be more dependent upon culturally-variable educational experience, whereas word-learning flexibility may be less dependent upon culturally-specific input.