A test of the instability hypothesis in low- and middle-income countries.

The instability hypothesis proposes that family structure transitions lead to negative child outcomes through the pathway of stress. However, in many cases, family structure transitions are not associated with stress or negative child outcomes, suggesting that there are specific circumstances under which transitions are more or less stressful. Using five rounds of data (ages 1-15) from the Young Lives study ( = 8,062) which follows children and their caregivers in Ethiopia, India, Peru, and Vietnam, we had two aims: (a) to test the instability hypothesis, and (b) to examine the specific circumstances under which family structure transitions lead to stress and worsened child physical health. First, we used multilevel mediation to assess whether financial stress mediated the link between family structure transitions and children's physical health. We then added household size, multigenerational household, and horizontally extended kin household as moderators to the family structure transition-financial stress relationship. We found that financial stress did not mediate the link between family structure transitions and children's physical health in any of the Young Lives countries. We found some moderated mediation effects for household size and multigenerational households in Peru and Vietnam, but effect sizes were small. These findings highlight the need to further unpack the instability hypothesis to understand the specific circumstances under which family structure transitions lead to stress and worsened child outcomes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).