Wowbagger said:
This is not a very good definition of instinct.
Nevertheless, this is the best we have. The problem is, an instinct is an inherent part of the organism. I'm not sure if it's in the DNA or not (not clear on how they form), but the organism will, unless damaged, ALWAYS do the action. You state that the test is to see if the individual needs to be trained away from the behavior, but in truth a better test is "Will the organism, if isolated from all others of its kind from birth, do the action the same way as the other organisms?"
This brings up the other problem with your examples: They are not behaviors, as such. Fear of heights may LEAD to behaviors, but fear is an emotional state, not a behavior. Protecting children is evern worse--look at the numerous ways that various cultures (and subcultures, and siblings within the same culture) protect their children. For an anecdotal example, I have friends who prevent their children from ever coming in contact with something that may hurt them, and I have other friends who go out of their way to expose their children to as many things, in controlled settings, as possible. Both are protecting their children. The first is protecting them right now, ensuring that nothing happens to hurt them today. The latter is protecting their children in the future, ensuring that their children can handle a wide variety of situations. And while we can debate which is better, the simple fact is that both ARE protecting their children. Compare that with a spider, which will always, unless it is damaged in some way, produce webs roughly the same. Crocs will always defend young making certain noises (they may eat them afterwards, but that's another issue). Ants know their job without training.
bowlofred said:
Are these "desires" characterized in some other way?
Yes: Desires, rather than behaviors. It's not instinctive to move to a cold place in the heat--it's a DESIRE. An instict would be "When the temperature reaches X, scuttle to the nearest shade". And while humans notice others due to chemicals we have little control over, our mating behavior is certainly not instinctive, not in the way that the mating behavior of, say, some birds is. And as far as finding something to eat when hungry, there are many who argue that we don't even know when we're hungry to begin with (thirst and hunger get wrapped up in one another). There's also the issues of WHAT food, WHEN to eat it, HOW to eat it, how to PREPARE it, etc., all of which would be covered by a truly instinctive behavior. A spider doesn't learn to eat the insects in its web (and most won't survive long enough to make the distinction between what is and what isn't good to eat [ie, what's food and what's predator] a learned behavior, because if they make a mistake there they'll probably die for their error).