Tender as an Oedipal nightmare
Tender's story is an allegorical telling of the Oedipal nightmare. He is constantly perplexed by feelings of deep emotional abandonment. These emotions are strong enough that he often becomes vengeful and wrathful, seeking to do actual murder. Why? Because he is trapped in a state of regression, constantly wanting life to be easier than it is. Why is that happening to him? He does not know, but to the extent that he voluntarily does evil, he fragments his ability to be healthy, much like he beats the life out of Adam.
Fertility as the divine female
Fertility's name is an attempt to tell the reader that this character represents something divinely female. She is divine because she brings forth new living beings with her womb, and Tender hates her for this. When Tender figures out that Fertility will need to abandon him in order to raise the baby safely, he decides there is nothing sacred, and he kills the new life, and the mother, and everyone on board the plane.
The motif of criminal insanity
Several scenes in the book share this motif, that the scene only really makes sense if the reader reads between the lines. The author uses an unreliable narrator to describe events, leaving room for the reader to believe that maybe Tender is not lying. The proof of his criminal insanity is that in the end, he realizes that he is insane and murderous, but he still goes ahead and kills everyone anyway.
Adam the scapegoat
By murdering his make-believe brother Adam, Tender makes Adam into a scapegoat. Now that Adam is "dead," he can take responsibility for the murders, or at least Tender can blame him. Also, Adam begs for death, while Tender gives death to many in the book, and also, Adam's name carries religious weight, since Adam is the first name given to a human being in the Abrahamic religions.
Psychic powers
The twin use of insanity and psychic power is confusing, because the insanity gives interpretive room for the reader to say, "All that psychic stuff is mumbo jumbo." But, then again, there seems to be some dark, witchcraft elements to Tender's behavior. He tends to view himself with religious grandeur. He believes he is famous. He believes he is bothered by the FBI. The question on the table is, do these psychic elements legitimately explain Tender's evil behavior, or is Tender simply an evil person?
