Happiness is not just a pleasurable experience to pursue as a goal, as hedonism prescribed. Human development does not simply mean health, formal education, and economic growth, as the UNDP’s index suggests. This paper proposes a new definition of ‘human development’: an increase in individual human skills that interact with the social and economic context in order to enable people to be the agents of their own lives, and then happy because satisfied with themselves. The hedonistic happiness-as-a-goal and this happiness-as-a-process are thus distinguished as two pathways to happiness with different properties and implications. The paper finally argues that while degrowth, as advocated for ecological reasons, may damage human development, policies for individual human development can encourage ecological behaviour.