I think that is too big a question to address in a series of messageboard posts, but I'll give it a go!
As I've stated in earlier posts, I believe that the one thing that really seperates us from the animals is our power of imagination (that is a very broad generalisation, I'm sorry). This has allowed humans to become better scavengers. For example, I could tell you where food is by giving you directions. If we had no power of imagination, I would have to take you to the food. In some cases a time of drought follows a time of plenty. We can imagine a time of drought, so we could store water and food for that time. But with this power of imagination comes questions and experimentation. Of course, humans eventually asked questions such as "Where do we come from?" and "What is our purpose?". Hence religion (sorry for the huge abbreviation, but I hope you can see what I'm getting at).
It's also tough to imagine the mindset of people throughout history. In certain times and places, I'd have probably been killed for writing this post.
More from me later,
Whirlwind
PS Thanks to everyone who replies to my posts, its nice to know that someone is listening to me!