Andrew’s mom tells him that she went to the store and bought…

Andrew’s mom tells him that she went to the store and bought enough cupcakes so that each member of the family could have one. Andrew really loves cupcakes, so he takes two. This results in one family member losing their cupcake. This is an example of:  

During a hospital stay, you observed a man and a woman, both…

During a hospital stay, you observed a man and a woman, both in health professional attire, talking to each other. You assumed that the man was a physician and that the woman was a nurse. Later, you found out the opposite to be true. What type of heuristic did you use during your initial reaction to the two individuals?