how pelayo and Elisenda treat the old man with enormous wings jnd what it tells us about human nature?

Elisenda and Pelayo force the old man to live in a chicken coop (they're rather afraid of him at first), and when the gawkers arrive to look at him they keep him there because he's a source of a great amount of money (they eventually build themselves a mansion).

As far as human nature, their treatment of the old man would certainly point toward greed. The two are never grateful for the fortune his presence affords them. They neglect him, and they continue to fear him for a very long time (in the very beginning a neighbor woman said he was an angel come to collect their sick child). The old man is branded like a possession and fed mush like an animal. Unfortuantely, this is human nature's less attractive side.