Answer:
Fear
Step-by-step explanation:
According to the book "Freak the Mighty" by Rodman Philbrick, Max and Kevin are two best friends who became close as a result of their disability.
Max is strong and powerful, but he has a learning disability, Kevin is brilliant but he has birth defects so he has to wear braces on his legs.
Max's first impression of Kevin was that he knows Kevin would be happy if he died. This initial reaction to Freak when he talks to him outside the house is one of fear.