In this paper we introduce a method to monitor interpersonal relations through a game with a social dilemma. In the game players can interact with each other through negotiations and by exchanges of resources. To enable the monitoring of interpersonal relations this environment confronts players with specially selected instances of the game, where strategies based on different social factors (like helpfulness or fairness) will enforce different choices in the game. An evolutionary inspired optimization was used to find the games with the special social setting. The special selection of the games helps us to relate the observed actions directly to parameters that model strategies that the players are likely to adopt. Through an estimation of these parameters we are able to observe quantitative differences in the social preferences by different players. Moreover, we demonstrate that players play differently depending on whom they are interacting with. This strongly indicates that the observed playing styles can reveal certain aspects of the relations between players.