An information processing system is configured to include a target vehicle data acquisition unit configured to acquire target vehicle data including a travel state of a target vehicle, driving operation information of the target vehicle, and position information of the target vehicle on a map, a behavior occurrence position recognition unit configured to recognize a behavior occurrence position that is a position where the target vehicle performs an unstable behavior, based on the target vehicle data, and a cause determination unit configured to determine whether or not the unstable behavior at the behavior occurrence position is caused by the driver, based on at least one of the travel state of the target vehicle and the driving operation information of the target vehicle.