To design for complexity in a healthy way, we need the ability to model humans as active participants.
What Comes After User-Centered Design?
Jeff Sussna

Great idea. And it concerns not only marketable products but also private and public services and government policies, including international development assistance. I would reformulate it as ‘we need the ability to appreciate humans as active participants exercising their free will’ in the entire cycle, from design through utilisation, to assessment and improvement.