What hierarchy of needs model is most valid?

Abraham Maslow created the original five level Hierarchy of Needs model, and for many this remains entirely adequate for its purpose. The seven and eight level 'hierarchy of needs' models are later adaptations by others, based on Maslow's work. Arguably, the original five-level model includes the later additional sixth, seventh and eighth ('Cognitive', 'Aesthetic', and 'Transcendence') levels within the original 'Self-Actualization' level 5, since each one of the 'new' motivators concerns an area of self-development and self-fulfilment that is rooted in self-actualization 'growth', and is distinctly different to any of the previous 1-4 level 'deficiency' motivators. For many people, self-actualizing commonly involves each and every one of the newly added drivers. As such, the original five-level Hierarchy of Needs model remains a definitive classical representation of human motivation; and the later adaptations perhaps serve best to illustrate aspects of self-actualization.