It is well known that there are considerable differences in length of life between people in different stratification layers. Those with higher education, higher income and from higher social classes live longer than others. Several explanations to this observation have been suggested, e.g. style of life, conditions early in life, and work load, to mention a few. Three more general suggested explanations will explored in this project.

One such general explanation is that differences in length of life are dependent on differences in intelligence. One suggested mechanism is that higher cognitive abilities will result in a better understanding of information of health determinants. This hypothesis will be explored by help of IQ measurement made at the compulsory conscription to military service for men at the age of 18.

A second general explanation is that it is the hierarchy of higher and lower positions in society, which leads to premature death among those in lower positions. Low status positions are supposed to increase death risks by leading to diminished self-respect and lesser control over various situations in life. We intend to approach this hypothesis by looking at the association between risk of death and prestige of status.

A third general hypothesis assumes that the cumulative exposition to strain over the life course increases the risk of illness and early death. We intend to look at social conditions an childhood and their interaction with conditions later in life in testing the credibility of this hypothesis.

Altogether new evidence from this project hopefully may provide a better understanding of social determinants to health and in the long run a better base for measures for an improved public health.