Published correlational effect sizes in social and developmental psychology

The distribution of effect sizes may offer insights about the research done and reported in a scientific field. We have evaluated 12,412 manually collected correlation effect sizes (Sample 1) and 31,157 computer-extracted correlation effect sizes (Sample 2) published in journals focused on social or developmental psychology. Sample 1 consisted of 243 studies from 6 journals published in 2010 and 2019. Sample 2 consisted of 5,012 papers published in 10 journals between 2010–2019. The 25th, 50th and 75th effect size percentiles were 0.08, 0.17 and 0.33, and 0.17, 0.31, and 0.52 in Samples 1 and 2, respectively. Sample 2 percentiles were probably larger because Sample 2 only included effect sizes from the text but not from tables. In text, authors may have emphasized larger correlations. Large sample sizes were associated with smaller reported correlations. In Sample 1 about 70% of studies specified a directional hypothesis. In 2010, no papers had power calculations while in 2019, 14% of p..., ,