uncertainty, we chose to take a conservative approach to estimating sample size. When sample size was only reported in terms of individuals, we took half the number to represent the number of pairs. When available, we used the number of complete pairs that had full data for at least two waves of data. When unavailable, we used reported attrition statistics to calculate the number of pairs that completed at least two assessments. Sample attrition or continued sampling are unlikely to exert a large influence on the current results as the majority of studies (k = 15) only reported information for two waves, and the maximum number of waves was 4. Estimating effect sizes from raw data would likely have resulted in smaller standard errors, as access to individual level data allows for powerful techniques that can handle missing data (e.g., full-information maximum likelihood estimation). Therefore, the reported results may be considered lower-bound estimates of precision.
