A method is provided to quantify and/or qualify psychological and physiological components of stress in mammals, in which a stimulus can be applied to the test subject's environment during the test. The method involves the steps of measuring one or more physiological and/or psychological characteristics before and after the administration of a stimulus to a test subject. The stimulus may consist of any product, task, aroma or the like that elicits a stress-related response upon administration. By analyzing the resulting measurements, and optionally comparing physiological and psychological characteristics where both are measured, an overall level of stress may be determined. The method of stress measurement may further be used in product development and/or testing.