Haptic shared control systems represent a useful approach for a safer and more intuitive cooperation between human and machines. For an adequate controller design, it is essential to understand the control behavior of a human during the interaction with a cooperation partner. A considerable amount of studies have shown that human behavior in a cooperative scenario is different than in a manual control task, indicating the need for modeling approaches which take the interaction into account. In this paper, we propose an approach to model haptic cooperative behavior of humans based on differential games, where the motion trajectories of each partner arise from the minimization of an individual cost function. We evaluate the applicability of the model for goal-oriented movements by means of an experiment consisting of 52 subjects moving a virtual marker cooperatively to a goal position. The interaction takes place through haptically coupled steering wheels. Moreover, we compare the differential game approach with another shared control model which considers the action of the cooperating partner as a system disturbance. The results show that the differential game model slightly outperforms the disturbance model in the approximation of observed motion trajectories with statistical significance.