The title of my presentation is ‘Action-Logics and World Leaders’ in which I apply a theory and model of adult development to the actions of a number of well-known leaders, including Donald Trump, Mark Zuckerberg, Boris Johnson, Justin Trudeau, Jacinda Ardern, Angela Merkel and Nelson Mandela, and ask, what is their ‘capacity’ for perspective-taking, awareness of time, openness to feedback and use of power in action and which of the action-logic stages does it most align with’? What the model shows is that Donald Trump is constructing his meaning from an Opportunist action-logic, Mark Zuckerberg from an Expert action-logic, Boris Johnson from an Achiever action logic, Justin Trudeau from an Achiever/Redefining action-logic, Jacinda Ardern and Angela Merkel from a Transforming Action logic and Nelson Mandela from an Alchemical action-logic. Why this matters and why it particularly matters to leadership in an interdependent world is then explored. Participants will also be given the opportunity to apply the four-parameter model (perspectives, timeframe, feedback and power) to a biographical episode from their own lives.