Life history theory is increasingly invoked in psychology as a framework for understanding differences in individual preferences. In particular, evolutionary human scientists tend to assume that, along with reproductive strategies, several behavioral traits such as cooperation and risk-taking and, in its broadest version, a range of psychological and personality traits also cluster into ‘fast’ and ‘slow’ life histories. However, the inclusion of such a wide range of traits in a life history strategy is founded on relatively little theoretical justification. Beyond environmental factors such as mortality risk, we argue that quantitative changes in resources - either embodied, physical or social - can lead to qualitative changes in people’s priorities and psychology. People use their resources to satisfy their different needs. People with access to fewer resources focus on their needs with the greatest marginal fitness benefit, while people with more resources can also afford to satisfy their needs with smaller fitness benefits. We show that, depending on the total amount of resources available, the optimal resource allocation of these resources differs, leading to the empirically observed ‘pyramid of needs’. In addition, the optimal allocation of resources shapes people’s risk and time preferences, which in turn affect a whole range of behaviors such as parenting style, cooperation, health, skill acquisition and exploration.