1. A behavior control system for causing an agent to carry out a task by emulating a behavior taken by an instructor to carry out the task, comprising: a trajectory generating element which generates a learning trajectory indicating a position of a second state variable in a time-series manner on a basis of a first model which represents a typical shape characteristic of a reference trajectory indicating, in a time-series manner, a position of a first state variable which is displaced with a motion of the instructor, and a second model which represents a motion of the agent in which the position and one or a plurality of n-th order time differential values (n=1, 2,. .. ) of the second state variable corresponding to the first state variable continuously change, wherein the motion of the agent is controlled according to the learning trajectory generated by the trajectory generating element.