Instinct vs Training

Here's an unusual story where a family discovered that their German Shepherd pulls people out of a pool when it sees them in the water. The family claims the dog has never been trained to do this. Given the dog's likely hereditary instincts to herd and protect, that may well be the case.

This example brings up the interesting point of nature vs nurture. How much of any canine behavior (good or bad) is based on genes, and how much on upbringing or training? That's a question for which there simply isn't a clear answer. Certainly it's a bit of both....