Hey, that's the spirit!!

The surest way to find out how he will do when faced with a survival situation is to put him into one of sorts. Get him out of his comfort zone a little, under conditions you can control but he can't and see how well he floats. He may not want to go willingly, he may whine and feign failure, but if it is set up right, it is almost impossible for him to continue in a non-participatory path. It will require some creative planning on your part, and you may have to set it up quite a bit, but where there's a will, there's a way.

Something simple like being 50 miles away from home and the car breaks down, and you don't have a cell phone, or it isn't working (in reality, you can emulate this without actually having to do without a phone, just in case), and you have to get home, or back to camp, or try signalling someone to help you out, etc. I hope you get the idea. Maybe make him responsible for solving a problem along the way, like figuring out which way to go next, or what else to try to start the fire with.

The point is get him in a situation where he is not in control and must react to the conditions. It may seem extreme, but what have you got to lose? Every time he responds in a positive manner, heap on the praise and admiration, maybe even astonishment, but make it genuine. Give him lots of physical contact, and be firm. He can't help but to become increasingly motivated.