The purpose of this study was to investigate the mediational role of relational psychological contract in social beliefs and work input attitude dependency. We analyzed data taken from employees in four different organizations operating in the Pomeranian market. A mediation analysis showed a strongly mediating role of psychological contract in the negative relationship between perception of life as a zero-sum game and work input. The motivational effect of the relational psychological contract, that is the role of job security, interesting work, (...) a career in the company, opportunities for promotion and other HRM practices prevail over the significance of personal beliefs, especially when these are negative. If the company lacks the appropriate HRM systems then day-to-day social exchanges can be crucial in modifying the social beliefs of the employee. (shrink)