  Recent research has taken particular interest in observing the dynamics
between altruistic and individual behavior. This is a commonly approached
problem when reasoning about social dilemmas, which have a plethora of real
world counterparts in the fields of education, health and economics. Weighing
how incentives influence in-game behavior, our study examines individual and
altruistic interactions, by analyzing the players' strategies and interaction
motives when facing different reward attribution strategies. Consequently, a
model for interaction motives is also proposed, with the premise that the
motives for interactions can be defined as a continuous space, ranging from
self-oriented (associated to self-improvement behaviors) to others-oriented
(associated to extreme altruism behaviors) motives. To evaluate the promotion
of individual and altruistic behavior, we leverage Message Across, an in-loco
two-player videogame with adaptable reward attribution systems. We conducted
several user tests (N = 66) to verify to what extent individual and altruistic
reward attribution systems led players to vary their strategies and motives
orientation. Our results indicate that players' strategies and self-reported
orientation of interaction motives varied highly significantly upon the
deployment of individual and altruistic reward systems, which leads us to
believe on the suitability of applying an incentive-based strategy to moderate
the emergence of individual and altruistic behavior in games.
