1. A system comprising: at least one computing device in communication with at least one presentation device and at least one physiological activity data acquisition device, wherein the at least one computing device is programmed by one or more instructions for: transmitting, to the presentation device, at least one instruction for presenting at least one of an image characteristic, a video characteristic or an audio characteristic to at least one member of a population cohort; obtaining at least one physiological activity measurement associated with at least one physiological response by the at least one member to the at least one of an image characteristic, a video characteristic or an audio characteristic previously presented to the at least one member from the at least one physiological activity data acquisition device; associating at least one indication of a mental state of the at least one member by comparing the at least one physiological activity measurement associated with at least one physiological response by the at least one member to stored mental state data indicative of a mental state of the at least one member; incorporating the at least one of an image characteristic, a video characteristic or an audio characteristic previously presented to the at least one member as an avatar attribute for at least one avatar associated with the at least one member based on the at least one indication of the mental state of the at least one member; and at least one of storing or presenting the at least one avatar associated with the at least one member and including the at least one of an image characteristic, a video characteristic or an audio characteristic.