Between- and within-subject covariance perspectives matter for investigations into the relationship between single- and dual-tasking performance

We expand the usually cross-sectional perspective on dual-tasking performance to include both intra- and interpersonal variability, which should capture within-person dynamics psychological processes better. Two simple tasks, first as single-, then dual-tasks, were performed by 58 participants over 20 sessions. found positive relationships between (1) single- (2) dual-task component tasks inter- intrapersonally. Better single-taskers better dual-taskers single-tasking sessions This implies shared capacities that covary intraindividually. conclude taking variability into account is a promising future perspective.