Key words: well-being, health, quality of life, social needs, social relationships, self-management, self-regulation, successful aging, intervention research, implementation research.

Nardi’s research contains two branches as subfields of the overall research line:

The first branch focuses on theory development (Steverink et al., 1998; Steverink et al., 2005; Steverink, 2014) and empirical research regarding the determinants of well-being during the life span in general populations and in specific populations of frail older people ("aging well and healthy"). Of particular interest are factors relating to social relationships, social needs and self-regulatory processes as determinants of well-being over the life span. The projects within this line of research mostly use large-scale empirical data sets and (since recently) also experimental studies.

The second branch builds on the first, but here the focus is on self-management intervention studies (by randomized controlled trials) for older people, and the actual implementation of the self-management interventions in health and welfare settings in the Netherlands (Steverink, 2009). The implementation part also contains research and runs under the heading of the "GRIP and GLEAM program" (Steverink, 2009), in Dutch: grip en glans.

The theoretical background of the research line consists mainly of two pillars:

(1) The importance of need-related mechanisms of self-regulation/self-management. Attention to basic need fulfillment is essential to the research line "Aging well: social relations, self-regulation, health and well-being". This line focuses on the influence of need fulfillment on self-regulation/self-management (including lifestyle risk factors, such as diet, physical activity, alcohol and tobacco use) and on psycho-social well-being (happiness). Both self-regulation and well-being are also hypothesized to be major intermediate variables for healthy aging and its trajectories (Steverink & Lindenberg, 2008).

(2) The importance of social context. The theoretical framework gives a central place to social context conditions that affect need fulfillment. These conditions range from broader social network-based resources available to individuals (Steverink & Lindenberg, 2006) - like the number and structure of social contacts, social integration, perceived levels of support, social status - to membership in associations or other formal organizations. These social context conditions not only provide social capital resources, which are instrumental in achieving an individual's goals and fulfillment of basic social needs, but also have a direct impact on individual health behavior and well-being, e.g. through rewarding specific types of behaviors. Influences of social context characteristics on self-regulation and well-being (via need fulfillment) are being investigated as important possible pathways that may explain the link between social context factors and health outcomes/trajectories (Steverink et al., 2011).