Table 1. Characteristics of study participants.

Characteristics	Number	(%) or mean (SD)
Cognitive ability at 8
Standardized to whole population	630	0.20 (0.79)
Educational attainment by 26	667
Vocational only	230	(34.5)
Ordinary level	189	(28.3)
Advanced level, degree or equivalent	248	(37.2)
Occupational attainment by 53	702
Professional/intermediate	296	(42.2)
Skilled, non-manual	252	(35.9)
Skilled, manual/partly skilled/unskilled	154	(21.9)
Marital status at 53	689
Single, never married	31	(4.5)
Married	557	80.8)
Divorced / widowed	101	(14.7)
Smoking status at 60–64	647
Current	61	(9.4)
Ex	357	(55.2)
Never	229	(35.4)
Physical activity at 60–64	633
Inactive	372	(58.8)
Less active (1–4/week)	105	(16.6)
More active (≥5/week)	156	(24.6)
Depression at 60–64*	628
Present	115	(18.3)
Not present	513	(81.7)
Psychological well-being at 52 (range of score, 7-42)
Autonomy	677	28.8 (4.7)
Environmental mastery	675	33.4 (5.6)
Personal growth	680	30.9 (6.0)
Positive relations with others	680	34.4 (5.6)
Purpose in life	652	31.8 (6.2)
Self-acceptance	667	28.5 (5.2)
Positive affect at 60-64 (range of score, 14-70)	580	52.0 (8.0)
Life satisfaction at 60-64 (range of score, 5-35)	579	13.3 (5.9)

SD, standard deviation.

Cognitive ability at 8 years was represented as the standardized sum of four tests of verbal and non-verbal ability devised by the National Foundation for Educational Research: reading comprehension, pronunciation, vocabulary, and non-verbal reasoning.

^*Presence of depression was measured as total score of ≥6 in the 28-item General Health Questionnaire

Domains of psychological well-being at 52 years were measured using the Ryff Scales of Psychological Well-being.

Positive affect at 60-64 years was measured using Warwick-Edinburgh Mental Wellbeing Scale.

Life satisfaction at 60-64 years were measured using the Diener Satisfaction with Life Scale.