Ken, а fоur-yeаr-оld, hаs never liked tо be held and avoids being hugged or kissed. He is withdrawn even from his mother and father. His mother says that he was hard to deal with as a child and was never affectionate to her or his father. She says, “He is so cold with us. When he was a baby, he wanted to be left in his crib. He cried when I picked him up. His grandmother tried to rock him, but he would cry more.” He is stilted and overformal in his speech. A solemn child, he enjoys solitary play and sometimes becomes focused on one activity to the exclusion of anything else. He also engages in self-soothing behaviors in new situations or with new people. Ken loves books and spends much time in his room with his toys. He is extremely concerned that his toys and books are kept in a specific order and in a specific place. Ken is interested in insects to the exclusion of most other things. His books and toys are focused on this interest. He is likely diagnosed with which of the following conditions?