Short Answer 
The term “zipper head” originated during World War II as a derogatory term for Japanese soldiers, referencing the shape of their helmets. This racial slur was used to dehumanize enemies and has had lasting negative implications on perceptions of Asian people.
Step 1: Understanding the Origin
The expression “zipper head” is primarily believed to have originated during World War II. This derogatory term was used to describe Asian people, particularly Japanese soldiers. Its roots lie in the shape of the soldiers’ helmets, which resembled a zipper when viewed from above.
Step 2: Context of Use During the War
During the conflict, soldiers from various nations often employed derogatory language to refer to their opponents. This practice aimed to dehumanize the enemy, and using terms like “zipper head” was part of a broader effort to diminish the humanity of Japanese soldiers.
Step 3: The Impact of Racial Slurs
The term “zipper head” served as a racial slur, reinforcing negative stereotypes and contributing to the overall dehumanization of Japanese individuals during the war. Such language had lasting implications, as it shaped perceptions and attitudes towards Asian peoples in the post-war era and continues to be recognized as a harmful expression.