Cognitive epidemiology – Bo Melin's research group

Bo Melins group investigate causal relationships between cognitive and emotional abilities in relations to health and e.g. acquired social positions later in life.


Cognitive epidemiology

Emotion and cognition and their relationships is a classic question within psychology. Increased knowledge about these basic entities in psychology is of importance also for other disciplines e.g. neuroscience and more direct applied areas.

Bo Melins group investigate causal relationships between cognitive and emotional abilities in relations to health and e.g. acquired social positions later in life. Bo Melins group is also interested in how these abilities relates to social mobility. Bo Melin has a long history and ongoing projects that relates to stress, work and health within a biopsychosocial frame.

Bo Melins group have shown that cognitive ability (or outcome from psychometric IQ test) is a strong predictor for various types of health outcomes and mortality. Cognitive ability was a pronounced predictor of all-cause mortality, cardiovascular disease (CVD)-mortality, mortality from violent causes, and alcohol-related mortality. Bo Melins group were among the first to obtain the striking finding of a pronounced gradient in mortality risk across all IQ score groups. Adjustment for socioeconomic position attenuated the increased risk somewhat. Except for the finding of a pronounced gradient other research groups have found similar findings in smaller and less representative samples. In conclusion, Bo Melins groups studies have shown that IQ test score measured in late adolescence was a significant predictor of all-cause, as well as cause-specific (CVD and injuries), mortality during 30 years of follow-up. The risk increased from high to low IQ test score results for all outcomes. After control for poverty we could show that poverty had only a small impact on the relationship between IQ scores and death. Although the gradient still were significantly pronounced after control for poverty, it was not clear from this study to what extent the increased relative risk associated with lower cognitive ability could be explained by other important risk factors. After adjustment for other important risk factors over the life course, the risk of e.g. cardiovascular heart disease (CHD) and acute myocardial infarction (AMI) associated with cognitive ability decreased substantially.

Cognitive ability tests have been used as predictors of achievement later in life (especially in relation to job performance) for almost a century. In one of the first comprehensive meta- analysis of the relation between intelligence a job performance (Hunter & Hunter, 1984) showed that cognitive ability measured psychometrically, was significantly associated with a wide variety of jobs including different complexity levels. The idea that social class may in part be a consequence on individual differences in cognitive ability is not doubt controversial and has important scientific and political implications. One argument that usually are brought forward in support for this assumption is that individual differences in intelligence precede and are more stable over time than socioeconomic factors and that both constructs are highly inter-correlated. Bo Melins group suggest it would be fair to say that these tentative assumptions about causality should lead the cognitive ability research to emphasize on the importance of acknowledging and understanding the social consequences of cognitive ability and to try to grasp over both constructs in future studies.

Emotional ability is a difficult construct and no consensus is to be found about definition and what to be included in the construct. It is referred as traits related to degree of Eysenck s neuroticism scale; to factors in the Costa and McCrae (1978) five factor model and other models. However, the five factor model with constructs related to low neuroticism, and high extraversion, agreeableness, and conscientiousness have been associated with longer life in one recent study and high neuroticism have been related to mortality in two recent studies. In the five-factor model study cognitive ability measures were available but did not test for interactions. This is somewhat surprising for it is conceivable that risks arising from psychological factors may be modified by other psychological factors.

A Biopsychosocial frame

Within a biopsychosocial frame, the conditions in which people are born, grow, live, work, and age is being fundamental to both understanding causes and taking action to redress health inequalities. That means, inequalities in health must be avoided by actions related to what we know contribute and reinforces these inequalities. Although differences in cognitive and emotional abilities reinforce these inequalities should a modern educational system have a pronounced agenda to reduce the influence of these reinforcing differences in abilities in relations to health?

Research projects

  • Increased stress with new mental task running
  • Cognitive and emotional abilities in relation to health


Selected publications