Confirmation bias is when you refer back to the first impression and that will makes your impression of that person. Basically it is hard to undo your first impression and it's a barrier because your perception of that person always relates back to your first impression. Stereotype is a barrier to impression formation because making a pre-judgment before talking to the person will cause a wrong reflection of the way they are. stereotype is when you make your prejudgment based off of who they hang around with and their cultural background. Over attribution is when you connect too much of someone's behavior to their characteristics. It is a barrier because your behaviors are differentiated from your characteristics and are rarely put together.
