How people actually decide, and what that means for the thing you are building.
Product work rests on assumptions about why somebody clicks, buys, returns or leaves, and most of those assumptions come from introspection. These replace introspection with research. Ordered from the broadest theory to the most directly applicable.
The foundation. Kahneman's two systems and the biases that follow from them sit behind most of what the other books here apply.
Cialdini's principles of persuasion, which appear in every growth tactic you have ever seen and are worth recognising by name.
The habit loop applied to product design. Read it for the mechanics, then read the last chapter for the question of whether you should.
Norman on affordances and mental models. It explains why a user does the wrong thing with an interface that seemed obvious to the team that built it.
The psychology principles most often cited in interface work, each stated in a page with the research behind it.
Jobs to be done as a theory of why somebody switches, which is a behavioural question wearing the clothes of a market one.
The research skill underneath all of it, which is following somebody else's reasoning without substituting your own.
A wider set of thinking tools, aimed at the decisions a product manager makes rather than the ones a user makes.