I have a comment to say about the Aztecs, Mayans and Incas. Why did they need to sacrifice people? Wouldn't it have been better to just have eaten bananas?

Maybe they sacrificed people because they weren't exactly sane, but seriously they had to have a reason to do it. Maybe they sacrificed humans so that maybe something good would happen. I'm not sure if something did. It might have been a good experiment, but it seems like they were just torturing their enemies and pleasing the gods that they worshipped.