Are good managers born or created?

A similar concept applies to teachers, in my profession. 
Some people are born teachers, or born managers. They have the qualities of a leader and
they are well-socialized to understand how to manage human relationships.  This is, to a
high degree, the most integral skill involved in both jobs.  Those that learn quickly,
and have an intelligence that allows them to both see the bigger picture management or
educational goals and strategies while still being able to both participate and direct
the actions of individuals that get them closer to those goals also tend to be natural
managers.

You can train someone to be a teacher or a
manager.  There are basic skills that can be acquired, and nuances of business and
education that can be learned. We have all worked for managers that have been effective
and ineffective, and while I would argue that some "trained" managers can be effective,
they tend to be less so, and are more often unsuccessful
altogether.