A recent study published in Biology Letters and publicized in a ScienceNow article studied temperature changes in women during social interactions. The researchers discovered that neutral conversation topics (which did not elicit any emotional response, as reported by the subjects), caused an increase in temperature by ~0.1 degree. Touching on the arm, palm, face, or chest (under the guise of re-positioning the temperature monitoring device) elicited as much as ~0.4 degree increase, particularly when the investigator was male (all of the subjects were female)! This indicates that our facial temperature changes simply through routine social interactions. The investigators do not know for certain why this happens, but they present several options, all of which depend on the person and/or the person they are interacting with being able to perceive the slight temperature changes in some way. Increased temperature is due to an increase in blood flow, so it is likely that the other person can judge the temperature changes based on skin coloration. The authors propose that temperature increases may act to increase perceived attractiveness (acting as a social cue), or the individual may alter their behavioral reactivity. However, it is unknown why this phenomena occurs, but it is an interesting one.