In one aspect, there is disclosed a system and method for rapidly and passively identifying changes in the number of open pores in the skin of an individual in response to a stimulus without contacting the individual. This is accomplished by using a thermal camera that is sensitive in the mid-wave or long-wave infrared (3-5 or 8-14 μmeters) to observe and/or count the number of skin pores opening in response to questions being asked of the individual.