Using a method developed in previous field studies of aggression, this study examined the influence of ambient temperature on responses to a car stopped at a green light. To investigate alternative models of the effects of high temperature on interpersonal hostility, the study was conducted during the spring and summer in Phoenix, Arizona, and included a range on the temperaturehumidity discomfort index up to 1 160. Results indicated a direct linear increase in horn honking with increasing temperature. Stronger results were obtained by examining only those subjects who had their windows rolled down (and presumably did not have air conditioners operating).

Higher ambient temperature leads to a linear increase in horn honking, particularly among drivers with windows rolled down.

Ambient Temperature and Horn Honking