Abstract: A simulated emotional state of a device is generated and maintained based on previous emotional state and contextual information. A trigger is associated with an effect value. For example, successful completion of a task may have an effect value of +5 while task failure may have an effect value of ?6. Upon occurrence of a trigger, an associated effect value of the trigger may be combined with a previously determined effect value to determine a function input value (FIV). The FIV is used as input to a function that provides an emotion value as output. The emotion value may then be used as input to determine a particular action. For example, if the emotion value corresponds to “happy”, the resulting action may be presenting an animation of a smile on a display device. As triggers occur, the function input value is updated, resulting in updates to the emotion value.