Talking about corporate culture has become quite popular in the business world. But why should companies care about corporate culture at all? Why do “soft” concepts like culture matter? Can’t companies simply rely on “hard” facts – the value of clear and efficient institutional rules and incentives? In this Public Paper, we argue that corporate culture is important because human behavior is always co-determined by the prevailing social norms. It is in the company’s interest to shape these norms through a cooperative culture that mobilizes employees’ voluntary cooperation in the pursuit of the firm’s performance goals. Our research provides behavioral foundations for cooperative cultures, based on important scientific insights from contract economics as well as from experimental and behavioral economics.