[MrsGoo]

It is a standard practice in war to try and de-humanize the enemy.
We are socially indoctrinated to not kill other people, so the de-humanizing is to overcome that by portraying the 'other' as not human and therefore OK to kill.

WWI the Germans had square heads (and ate children)
WWII the Japanese were, ... oops also very similar to the Chinese who were our allies.
Vietnam - not people but Gooks!! whatever that means.
In the mid East I have seen the term 'towelheads'

and in a history class I have viewed a chilling movie made by the Nazis for occupied Holland portraying Jews as rats. Apparently successful as that country 'gave up' a higher percentage of their jews than any other occupied country.

After WWII's genocides became known "never again" was the cry.
Biafra
Congo
Rwanda
Cambodia
Dafur
Bosnia
Iraq (shiite under Saddam)

Africa, Asia, and Europe, from a continental perspective Antartica seems to have no genocides.
Unfortunately things have not improved