Are some people more prone to developing corns than others?

Yes. Calluses and corns are thickened dead skin material, and form naturally to protect areas of skin where there is repeated pressure or frequent friction. People whose feet bones are formed a way that causes more pressure or friction spots during walking will tend to get corns more easily. Poorly fitting shoes and excessive walking, running, or climbing may increase calluses and corns, too.
Yes. Some people who have toe deformities like hammertoes or claw toes are prone to corns.