Why does Holden have such an easy time lying to others, even his teacher? What does this say about his morality and respect for elders?

Holden justifies his lying by thinking he is intellectually and socially above adults: adults are phony and he is authentic. Lying is just a coping mechanism that helps Holden grasp his tenuous sense of reality. This shows Holden to be rather immature even though his observations often have a ring of truth to them