[@Duoya][@Neo Is Delight]

I'd go with Lack of Empathy or Lack of Understand Empathy

Empathy means - the ability to understand and share the feelings of another

Apathy means - “a lack of interest, enthusiasm, or concern” 

Apathy wouldn't work in this case because he simply doesn't understand empathy, that doesn't mean he completely lacks it or lacks interest, enthusiasm or concern.

Unless that is what you mean Duo