Social inequalities in mortality and health have been recognised as serious public health issues since the 1980s, yet researchers continue to find social gradients in health nearly everywhere they look.1,2 Despite decades of research, our understanding of how and when socioeconomic factors and health interact to produce health inequalities remains work in progress. Some research on health inequalities has extended focus from adulthood social position to parental social background and early life conditions, and the accumulation of advantage and disadvantage across the life course.