Antisemitism or Human Nature?

What's at the root of strong dislike or hate?

Genesis 4:5-12

5 But unto Cain and to his offering he had not respect. And Cain was very wroth, and his countenance fell.

6 And the Lord said unto Cain, Why art thou wroth? and why is thy countenance fallen?

7 If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him.

8 And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.

9 And the Lord said unto Cain, Where is Abel thy brother? And he said, I know not: Am I my brother's keeper?

10 And he said, What hast thou done? the voice of thy brother's blood crieth unto me from the ground.

11 And now art thou cursed from the earth, which hath opened her mouth to receive thy brother's blood from thy hand;

12 When thou tillest the ground, it shall not henceforth yield unto thee her strength; a fugitive and a vagabond shalt thou be in the earth.