Despite being an established feature of social science research in high-income countries, the cost and complexity of longitudinal studies mean they are a comparative rarity in low- and middle-income countries. This chapter examines longitudinal evidence from the Young Lives study in Ethiopia, India, Peru and Vietnam to analyse how inequalities between groups of children become established. First, the chapter identifies that developmental differences between groups of children emerge very early in life. Second, while children's height development trajectories are sometimes thought of as 'fixed' early in life, cohort data shows later change in individual trajectories which offers potential intervention points across the life-course. Third, life-course analysis has a particular strength in showing the interdependencies between domains of children's development as they grow up. Finally, this chapter discusses challenges of linking longitudinal evidence with policy debates, emphasising the importance of involving policy actors early in the research process to identify policy demand for research and support effective dissemination and uptake.

Handbook of the Life Course, Vol 2, edited by Michael J. Shanahan, Jeylan T. Mortimer and Monica Kirkpatrick Johnson, Springer, 2015.