The relationship between temperament, polygenic score for intelligence and cognition: A population-based study of middle-aged adults

We investigated whether temperament modifies an association between polygenic intelligence potential and cognitive test performance in midlife. The participants (n = 1647, born between 1962 and 1977) were derived from the Young Finns Study. Temperament was assessed with Temperament and Character Inventory over a 15-year follow-up (1997, 2001, 2007, 2012). Polygenic intelligence potential was assessed with a polygenic score for intelligence. Cognitive performance (visual memory, reaction time, sustained attention, spatial working memory) was assessed with CANTAB in midlife. The PGSI was significantly associated with the overall cognitive performance and performance in visual memory, sustained attention and working memory tests but not reaction time test. Temperament did not correlate with polygenic score for intelligence and did not modify an association between the polygenic score and cognitive performance, either. High persistence was associated with higher visual memory (B = 0.092; FDR-adj. p = 0.007) and low harm avoidance with higher overall cognitive performance, specifically better reaction time (B = -0.102; FDR-adj; p = 0.007). The subscales of harm avoidance had different associations with cognitive performance: higher "anticipatory worry," higher "fatigability," and lower "shyness with strangers" were associated with lower cognitive performance, while the role of "fear of uncertainty" was subtest-related. In conclusion, temperament does not help or hinder one from realizing their genetic potential for intelligence. The overall modest relationships between temperament and cognitive performance advise caution if utilizing temperament-related information e.g. in working-life recruitments. Cognitive abilities may be influenced by temperament variables, such as the drive for achievement and anxiety about test performance, but they involve distinct systems of learning and memory.

Adult temperament and childbearing over the life course

Emerging evidence suggests that temperament may predict childbearing. We examined the association between four temperament traits (novelty seeking, harm avoidance, reward dependence and persistence of the Temperament and Character Inventory) and childbearing over the life course in the population‐based Cardiovascular Risk in Young Finns study (n = 1535; 985 women, 550 men). Temperament was assessed when the participants were aged 20–35 and fertility history from adolescence to adulthood was reported by the participants at age 30–45. Discrete‐time survival analysis modelling indicated that high childbearing probability was predicted by low novelty seeking (standardized OR = 0.92; 95% confidence interval 0.88–0.97), low harm avoidance (OR = 0.90; 0.85–0.95), high reward dependence (OR = 1.09; 1.03–1.15) and low persistence (OR = 0.91; 0.87–0.96) with no sex differences or quadratic effects. These associations grew stronger with increase in numbers of children. The findings were substantially the same in a completely prospective analysis. Adjusting for education did not influence the associations. Despite its negative association with overall childbearing, high novelty seeking increased the probability of having children in participants who were not living with a partner (OR = 1.29; 1.12–1.49). These data provide novel evidence for the role of temperament in influencing childbearing, and suggest possible weak natural selection of temperament traits in contemporary humans. Copyright © 2009 John Wiley & Sons, Ltd.

Type A behaviour and school achievement

Type A behaviour related to school achievement was studied in 1640 randomly selected 12‐, 15‐, and 18‐year‐old subjects. Type A behaviour was both self‐assessed by the subjects and evaluated by their mothers. Results indicated that school achievement was not related to the global score of Type A behaviour but correlated with three Type A dimensions, i.e. positively with Responsible Hard‐driving and Leadership Competitiveness, and negatively with Aggressive Competitiveness. It has previously been shown that hard‐driving correlates with a high level of somatic CHD risk factors, while leadership competition is a protective factor, i.e. it is associated with a low level of somatic CHD risk. So, school achievement differentiated adjusted and maladjusted Type A competitors, but not individuals with high and low somatic CHD risk. The results were manifest for boys and girls and for all age groups. Moreover, it was shown that the results were obtained independently of the methods used.

Type A behaviour and types of competitor in young adults

A previous study (Keltikangas‐Järvinen and Räikkönen, 1990a) discovered two different Type A competitors among adolescents, i.e. adjusted and maladjusted competitors. This paper examines whether the same result can be replicated in older age groups. Type A behaviour, self‐esteem, locus of control, and achievement striving were measured in 935 randomly selected young adults. Two different kinds of Type A competitor were found, i.e. aggressive and hard‐driving. Neither of these two could be called ‘adjusted’. Instead, adjusted and maladjusted forms of striving for achievement were found which adequately described the previously found adjusted and maladjusted types of competitors. The results suggest that achievement striving is a very essential dimension of Type A behaviour. However, it may play a different role in different psychological contexts.

Difficult temperament predicts self‐esteem in adolescence

A six‐year longitudinal study investigated the impact of maternal hostile child‐rearing attitudes, role dissatisfaction, and maternal perceptions of adolescent temperamental difficultness on self‐esteem in late adolescence, after controlling for the initial self‐esteem measured in early adolescence. Adolescents (n = 313), derived from the Cardiovascular Risk in Young Finns study, rated their self‐esteem at the study entry at age 12, and six years later at age 18. Maternal reports of child‐rearing attitudes, of role satisfaction, and of the temperament of the adolescent were obtained at the study entry and three years later. Mother's perceptions of adolescent's temperament as difficult at ages 12 and 15 predicted adolescent's self‐reported self‐esteem in late adolescence, whereas earlier self‐esteem did not predict later perceptions of temperament or parenting. We found no evidence that maternal perceptions of parenting indirectly, or after controlling for the initial level, predicted adolescent's self‐reported self‐esteem. Copyright © 2002 John Wiley & Sons, Ltd.

Adult attachment dimensions and recollections of childhood family context: associations with dispositional optimism and pessimism

The present study tested the theoretically inferred but not yet empirically tested association between dispositional optimism–pessimism and attachment security among 423 Finnish women and men. A second‐order latent variable representing a generalized representation of attachment insecurity in close relationships that included two latent constructs, the one representing romantic adult attachment dimensions and the other representing recollections of attachment‐related childhood family relationship, was associated with greater pessimism; the adult attachment dimension of high anxiety had unique and additional explanatory power, not accounted for by the generalized representation of attachment‐related insecurity. The model explained 48% of the variance in pessimism. The results clearly emphasize that additional studies are needed to clarify the role of interpersonal processes in dispositional optimism–pessimism. Copyright © 2004 John Wiley & Sons, Ltd.