Table 1.
Descriptives for midlife cognitive performance, cortisol measures and childhood cognition and educational attainment in the British 1946 birth cohort; mean (SD) shown unless specified.
| Variables | Males | Females | p-Value |
|---|---|---|---|
| Cognitive performance at 60–64: | |||
| Verbal memory | −0.19 (0.96) n = 804 |
0.19 (0.99) n = 933 |
<.001 |
| Letter search speed | −0.08 (0.99) n = 819 |
0.06 (0.99) n = 944 |
.003 |
| Reaction time | 0.00 (1.01) n = 814 |
−0.07 (0.88) n = 934 |
.12 |
| Cortisol at 60–64 (nmol/L): | |||
| Wakening | 21.7 (11.4) n = 780 |
18.8 (9.2) n = 894 |
<.001 |
| 30 min after awakening | 26.6 (11.9) n = 722 |
26.4 (11.1) n = 809 |
.68 |
| Evening | 3.42 (4.96) n = 691 |
3.38 (3.84) n = 780 |
.84 |
| Cortisol awakening response | 4.80 (11.9) n = 614 |
7.34 (11.6) n = 699 |
.001 |
| Diurnal drop | 23.9 (12.4) n = 547 |
23.9 (11.5) n = 608 |
.92 |
| Childhood cognition: | |||
| Cognitive ability at 8 | 0.11 (0.99) n = 745 |
0.17 (0.93) n = 847 |
.26 |
| Cognitive ability at 11 | 0.17 (0.95) n = 733 |
0.20 (0.89) n = 817 |
.47 |
| Cognitive ability at 15 | 0.29 (0.96) n = 712 |
0.14 (0.87) n = 810 |
.001 |
| Overall childhood cognition | 0.21 (0.96) n = 757 |
0.18 (0.88) n = 846 |
.64 |
| Educational level at 26: | <.001 | ||
| Degree or higher | 18.2% n = 144 |
6.6% n = 60 |
|
| GCE ‘A’ level, Burnham B or A2 | 30.6% n = 242 |
27.0% n = 244 |
|
| GCE ‘O’ level or Burnham C | 13.5% n = 107 |
26.6% n = 241 |
|
| Sub GCE or vocational course | 6.3% n = 50 |
9.5% n = 86 |
|
| None | 31.4% n = 248 |
30.3% n = 274 |
|