The potential of life course research. David Blane ESRC International Centre for Life Course Studies in Society and Health (ICLS).

Preamble. Matthias Richter: Bielefeld ZIF workshop 2010; health inequalities, epidemiology, genetics. Dimitri Mortemans: where’s the sociology & demography? Summer School on longitudinal & life course research; designed to bring together demography, epidemiology & sociology. Antwerp 2011 & 2012; Oxford 2013; Amsterdam 2014; Bamberg 2015; Milan 2016.

Life course perspective. Looks for the influence of the past on the present. Investigates whether such influences are direct, or indirect via contemporaneous factors. Tests the socially and biologically plausible pathways between the past and the present. Characterised by inter-disciplinarity, use of longitudinal data, socio-historical context.

Three traditions. Demography: interested particularly in mortality and fertility. Sociology: strong interests in family formation & dissolution, labour market participation and social mobility. Epidemiology: mortality, morbidity and health are main outcomes of interest; enthralled currently by genetics, at cost of Virchow’s legacy.

Comments. There are more than three traditions: Glen Elder’s work within social psychology; and others. Each tradition has much to teach the others; for example the biomedical critique of self- assessed health (objective, subjective). United by a shared interest in longitudinal data and the statistical methods for their analysis.

Origins The life course now is a core theme in social epidemiology. 1990s

Model: Accumulation Disadvantages, or advantages, tend to cluster cross-sectionally occupation + residence + area of residence + consumption and accumulate longitudinally. childhood + adulthood + older ages This social process may have a major impact on health through the accumulation of numerous relatively minor effects.* * Blane et al European J Public Health

Model: Critical periods Extends the idea of biological programming to include Childhood Psycho-social stress at the time of brain maturation may both inhibit child growth and mis-set the developing BP control mechanisms, producing later high BP* Social development Key social transitions** * Montgomery et al Archives Disease Childhood ** Bartley et al British Medical Journal

Model: Pathways Early advantage or disadvantage sets a person on a pathway to a later exposure that is the aetiologically important event.* Educationally successful women (pathway) tend to delay their first pregnancy (aetiologically important event), which increases their risk of breast cancer. * Power & Hertzman British Medical Bulletin

Real life: child growth, adult occupational strain & blood pressure in early old age. Slow growth during childhood is associated with raised systolic blood pressure during early old age and with high exposure to occupational strain during adulthood. High exposure to occupational strain during adulthood interacts with slow growth during childhood to further increase systolic blood pressure during early old age.

Models: A judgement Models are difficult to distinguish empirically* and conceptually** Perhaps best to see accumulation as the general social process which drives life course trajectories; with critical periods and pathways, in addition to accumulation, being the biological processes of disease causation** * Hallqvist et al.2004 Social Science and Medicine ** Blane et al Revue d’Epidemiologie et de Sante Publique

Here’s another example: Contemporary increase in life expectancy at middle age (mortality rates in pre-SPA quinquennium fell by two-thirds during ). Explanations tend to be disease-based (CHD) and consider only medical care and risk factor change. But all main causes of death fell by similar amounts. What would be a life course approach?

Strachan-Sheikh model

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Growth & development: Social policy and social science context: Pre-WWI: Rowntree surveys of poverty (standard of living life cycle); 1904 Inter-departmental Committee (school meals). 1930s: Boyd Orr surveys of child nutrition; Family Endowment Society (family allowances). WWII: Beveridge Report; full employment; food rationing. Post-WWII: welfare state.

Working life: /1993. Socio-economic context: Spread of nuclear family; fewer children; better housing. Full employment (to mid-1970s). Rising real wages; nutrition. Holidays; shorter working week. Labour market niches; early retirement; disability benefit.

Retirement: 1988/ Emergence of Third Age (end of employment & family responsibilities to loss of functional independence): Occupational & private second pensions. Functionally healthy. Self-realisation & pleasure. Social participation & networks confer resilience in face of adversity of ageing. Nutrition; exercise. Minimum Income for Healthy Living for retired.

Life course questions. Are the drivers of increasing longevity the same as those driving socioeconomic differences in longevity? Is the biological effect of these improvements in the conditions of life cumulative or are there critical periods? Which social policies address past disadvantage as well as present need?