Families, broadly conceived, are multiply determined and determining systems whose functioning and well-being are sensitive to a range of contexts, including the dynamic policy context across the full range of policy domains. Particular political attention with strong normative overtones is often given to families with particular characteristics experiencing social exclusion in particular ways and associated with particular (undesirable) policy outcomes. Debatably, one important role of the 'public' academic is to contribute to the policy process by providing expert commentary on the assumptions and evidence-base on which policy is founded, and on the evaluation of its tangible products. This thesis reflects on the candidate's experience of over a decade's worth of engagement with policy and evidence that either relates, or is argued should better relate, to the functioning of families in contexts of extreme social exclusion and experiencing significant family stress. Prima facie, the three substantive areas cover by the selected papers: early years support, youth gang policy, and bereaved family activism, might seem unconnected, however, they represent a strongly linked narrative arc of research and writing that offer common themes and intellectual progression. At the heart of both early years and youth gang work are questions of how best to frame and configure interventionist policy aimed at preventing negative outcomes (health, behaviour, life-chances) for socially-excluded children and adolescents while, at the same time, avoiding policy misdirection, stigmatisation and coercion. In a late modern, austere Britain, how can the State credibly claim to reduce harms of these kinds when policy is often a net contributor to/creator of them? At the heart of youth gang and bereaved family papers are questions of how best to support the sometimes-blamed, often-overlooked secondary victims of serious violence. How is (often extreme) stress experienced by affected families, what vulnerabilities does it express and create, and to what extent can it be used as a motivator of defiant action? The thesis concludes with a discussion of the various modes of academic engagement displayed across the work, specifically, the developmental progression of the author from 'professional', to 'policy', to 'critical', to 'public' modes of doing research on family stress. The personal rewards and costs of persistence in the face of limited policy impact are stressed.