A tendency toward evil?

One extension of this topic might be the unlikely occurrence involving the Ishmaelites in the course of [Genesis] ch. 37. It is interesting that both Esau’s and Joseph’s brothers’ moment of hatred and murderous intent is accompanied in the story by the appearance of Ishmael’s descendants (Gen 28:9; 37:25, 28; 39:1). At the time that they contemplate getting rid of the favored one, the unchosen brothers unite with the unchosen descendants, emphasizing perhaps the negative tendency that unchosenness entails.—The Unfavored, page 18 n. 7