Four of the articles published in this special section of "Developmental Psychology" build on and refine psychosocial acceleration theory. In this short commentary, we discuss some of the adaptive assumptions of psychosocial acceleration theory that have not received much attention. Psychosocial acceleration theory relies on the behavior of caregivers being a reliable cue of broader ecological conditions and on those ecological conditions being somewhat stable over the individual's lifetime. There is a scope for empirical and theoretical work investigating the range of environments over which these assumptions hold, to understand more deeply why it is that early life family environment exerts such reliable effects on later life-history strategy.