Table 4.
Average Cognitive Test Scores and Computed Dispersion Scores Across Studies
| Cognitive tests, aligned according to cognitive domains | ||||||||
|---|---|---|---|---|---|---|---|---|
| Working memory | Declarative memory | Fluid intelligence | Crystalized intelligence | Visuospatial reasoning | Speed | Verbal fluency | Computed cognitive dispersion score | |
| Study | M (SD) | M (SD) | M (SD) | M (SD) | M (SD) | M (SD) | M (SD) | M (SD) |
| CogUSA | 516.73 (22.36) | 11.11 (3.20) | 55.53 (10.79) | 55.55 (11.10) | 51.25 (9.92) | 534.65 (28.25) | 0.70 (0.27) | |
| ELSA | 4.59 (2.16) | 4.26 (1.95) | 5.75 (2.25) | 0.75 (0.40) | ||||
| HRS | 9.75 (3.25) | 508.34 (40.34) | 1.87 (0.50) | 0.72 (0.54) | ||||
| LBLS | 17.77 (2.44) | 11.27 (6.75) | 18.29 (10.97) | 33.23 (12.53) | 0.71 (0.35) | |||
| MIDUS | 4.96 (1.53) | 4.36 (2.63) | 2.18 (1.53) | −1.10 (0.29) | 18.85 (6.17) | 0.77 (0.34) | ||
| SATSA | 9.68 (2.15) | 20.60 (4.62) | 30.91 (8.41) | 18.44 (7.70) | 38.38 (12.29) | 0.71 (0.27) | ||
| WLS | 5.63 (1.42) | 3.44 (1.79) | 8.39 (3.67) | 11.15 (4.17) | 0.82 (0.36) | |||
Note. All reported values are raw scores, except speed for MIDUS, which is transformed so that higher values indicate better cognitive performance (these values were standardized prior to analysis). CogUSA = The Cognition and Aging in the USA; ELSA = English Longitudinal Study of Aging; HRS = Health and Retirement Study; LBLS = Long Beach Longitudinal Study; MIDUS = Midlife in the United States; SATSA = Swedish Adoption Twin Study of Aging; WLS = Wisconsin Longitudinal Study. See study description in text and Table 3 for specific cognitive tasks administered aligned according to cognitive domains.