how does freud believe repression leads to civilization and what the negatives consequences are?

Freud argues that civilization is intrinsically inimical to human happiness. The process of "civilizing" the human being involves stifling or repressing many of the sexual impulses that lead most directly to pleasure. Freud also notes that participation in civilized life entails the renunciation of one's aggressive impulses. Thus, to be civilized we must do without the two strongest claims to our instincts, sex and violence. These two pleasures find sublimated outlets in various activities - sports instead of violence, for instance - but this fulfillment cannot replace the direct experience of instinct-fulfillment found in simpler social organizations. As Freud writes, "If civilization requires such sacrifices, not only of sexuality but also of the aggressive tendencies in mankind, we can better understand why it should be so hard for men to feel happy in it. In actual fact primitive man was better off in this respect, for he knew nothing of any restrictions on his instincts."