Human social and psychological processes typically have an individually variable and time-varying nature. Consequently, generalizing inferences on group-level to individual experience is tricky. This problem of non-ergodicity is illustrated in six samples (≥87 participants and an equal number of assessments per participant). The group-level correlation between worry and depressed mood (r= 0.71), for example, the cardinal features of anxiety and depression, is lower at the individual level (r= 0.32) and ranges from -0.11 to 0.89. Because intraindividual covariation proves to be 2-4 times larger than around group estimates, only 68% of the individual correlational values fall within a range that would be predicted by group-level data to cover 99.7% of all possible correlations: a discrepancy of nearly 32%. Additional examples and potential consequences are presented at our symposium.
International Conference of Psychological Science: null