Step-by-step explanation:
The concept illustrated in this situation is often referred to as "In-group Bias" or "In-group/Out-group Bias." In this case:
In the classroom: People are familiar with Isaac, and he is part of their "in-group" because they see him regularly. As a result, they are more accustomed to his wheelchair, and it becomes less of a focal point.
In public: When Isaac is in a public setting, people may not know him personally, and he becomes part of the "out-group." People tend to notice differences in the out-group more, and this includes paying more attention to his wheelchair.
This concept highlights how individuals tend to be more accepting and less focused on differences when they are familiar with a person or part of the same group but may exhibit biases or heightened awareness of differences when encountering individuals from outside their familiar group.