In this essay, we honour the memory of Oliver Williamson by reflecting on Chiles and McMackin's 1996 Academy of Management Review article 'Integrating variable risk preferences, trust, and transaction cost economics'. The article, which built on Williamson's work in transaction cost economics (TCE), went on to attract attention not only from the authors' home discipline of management and organisation studies, but also from other business disciplines, the professions and the social sciences. After revisiting the article's origins and core arguments, we turn to selectively (re)view TCE's development since 1996 through the lens of this article, focusing on trust, risk and subjective costs. We cover conceptual and empirical developments in each of these areas and reflect on how our review contributes to previous debates concerning trade-offs implicit in relaxing TCE's behavioural assumptions. We conclude by reflecting on key points of learning from our review and possible implications for future research.