This document discusses a new paradigm for leadership development based on understanding the four functional areas of the brain and how they relate to different leadership styles. It presents a model of four types of leadership based on the brain's functional quadrants: business leadership focused on results from the left rational brain; strategic leadership providing vision from the right rational brain; social leadership focused on relationships from the right emotional brain; and process leadership ensuring procedures from the left emotional brain. It argues that most leaders only use one or two functions, limiting their effectiveness, and that leadership programs should target brain development rather than just behaviors to facilitate whole-brain leadership. Tools are proposed for developing individual leaders' brain functions and embedding whole-brain approaches into organizational systems and culture.