Solving difficult problems well typically involves some form of root cause analysis. A novice looking at a broken thing may decide to simply replace it and move

Solving difficult problems well typically involves some form of root cause analysis. A novice looking at a broken thing may decide to simply replace it and move on with the day. You can mindlessly replace widgets very rapidly. A master looking at the same might be more inclined to ask "why" a few times and set up some additional calls with the customer. I don't think this really has anything to do with "intelligence" as much as it does patience.