Abstract: An electronic device that provides a virtual representation is described. During operation, the electronic device may receive sensory inputs associated with a user. Then, the electronic device may determine one or more behavioral or emotional inputs based at least in part on the sensory inputs. Moreover, the electronic device may compute a modification to a behavioral or an emotional response of a virtual representation based at least in part on the one or more behavioral or emotional inputs, a behavioral and emotional model, and a set of predefined or predetermined parameters, where the behavioral and emotional model includes one or more purposes that reflect a personality of the virtual representation, and where a given purpose models an expected reward associated with a given need of the virtual representation. Next, the electronic device may provide or present the modification to the behavioral or the emotional response of the virtual representation.