In the U.S., there was a widely propagated view that the Japanese were subhuman. There was also popular anger at the Japanese surprise attack on Pearl Harbor, amplifying pre-war racial prejudices. The U.S. media helped propagate this view of the Japanese, for example describing them as “yellow vermin”. In an official U.S. Navy film, Japanese troops were described as “living, snarling rats”. The mixture of underlying American racism, which was added to by U.S. wartime propaganda, hatred caused by the Japanese war of aggression, and both real and also fabricated Japanese atrocities, led to a general loathing of the Japanese. Although there were objections to the mutilation from amongst other military jurists, “to many Americans the Japanese adversary was no more than an animal, and abuse of his remains carried with it no moral stigma”.
According to historian Niall Ferguson: “To the historian who has specialized in German history, this is one of the most troubling aspects of the Second World War: the fact that Allied troops often regarded the Japanese in the same way that Germans regarded Russians — as Untermenschen”. Since the Japanese were regarded as animals, it is not surprising that Japanese remains were treated in the same way as animal remains. Another historian Simon Harrison comes to the conclusion. “Skull trophies of the Pacific War: transgressive objects of remembrance“, that the minority of U.S. personnel who collected Japanese skulls did so because they came from a society that placed much value in hunting as a symbol of masculinity, combined with a de-humanization of the enemy.