start to remind him to realize the suffering of others, by pointing out the hardships others around him may be experiencing. If you pay enough attention, it's not difficult to do. You seem already doing it.
You don't have to worry about his intelligence.
Can you share a moment with him, such as enjoying an ice cream TOGETHER?
Try to have him understand how YOU are feeling, first. Have him do chores with you. Have him do physically challenging tasks.
