Background: Human wellbeing consists of dynamic interactions and feedback loops across multiple life domains, a perspective increasingly emphasised within positive psychology’s systemic and strengths-based approach to flourishing. This study develops a systemic framework to model these interdependencies and examines how cross-domain investment can optimise both domain-specific and integrated wellbeing across the lifespan. Methods: Using a Cobb–Douglas functional form with associated growth and resource constraints, we formalise the interaction between physical and financial wellbeing as an example and analyse their joint contribution to overall wellbeing. Results: The model demonstrates that improvements in one domain of wellbeing can enhance wellbeing in another, thereby shifting the optimisation frontier. While narrow domain-specific wellbeing strategies are subject to larger diminishing marginal returns, cross-domain investment generates reinforcing effects that elevate both domains simultaneously and increase integrated wellbeing. Conclusions: In line with positive psychology’s focus on leveraging strengths to support areas of relative weakness, the findings show how developing one domain of wellbeing can mitigate constraints in another. These findings align with positive psychology’s emphasis on multidimensional flourishing and resource-building processes, highlighting the importance of systemic resource allocation and suggesting that wellbeing optimisation requires coordinated, contextualised multi-domain strategies rather than siloed approaches.
Wet et al. (Sun,) studied this question.