4) The person in question maintains few friendships in his or her own age bracket.
Because the perverted interests of a predator are so abhorrent to the general populace, there are few people with whom genuine, open friendships can be formed. He or she often appears to be a loner. Friendliness may be expressed more to children or teens who may give the respect naturally given to an adult, but so often lacking in the life of the person in question.