Answer:The fundamental attribution error
Explanation:
The fundamental attribution error which is also referred to as overattribution error occurs when we relate someone's action to their personality whilst neglecting situational factors that may contribute to their behaviour.
We assume that when someone does something it is because of the type of person that they are and we don't consider any social or environmental factors that may contribute to their behaviour.
Rather than thinking that Ralph is an idiot it could happen that he didn't see the sign , maybe it was hidden from Ralph's sight.