…particularly in the way that no matter how far we develop and distance ourselves from the wild creatures which lack the wheel and the written word and the industrial war machine, our behavior often mirrors that of far simpler organisms than ourselves. Perhaps there exist certain universal truths…
That’s certainly an interesting interpretation, but it’s definitely not what’s occurring. Your explanation is full of anthropomorphism, assigning critical thinking skills and emotions to animals that are just not capable of that level of complexity. Crabs aren’t spiteful, they’re purely selfish just like all other solitary species. If the crabs in the bucket pull their escaping conspecifics back into the bucket, it’s most likely by accident as the trapped crabs try to use the escaping crab for purchase to make their own escape. They’re not thinking, “That other crab is escaping! I’d best pull it back here so we can continue fighting!” They may not even recognize the other crab as a crab in their own blind panic.
As for the similarity between human and animal behaviour, it’s most likely due to the limits of evolution. We all share a similar evolutionary history to an extent, and that history dictates what emotions and behaviours we can display. For example, all animals can show aggression under stress; it’s something an ancestral species developed that we’ve all held onto. Recent evolution and environmental factors (including the literal environment, social situations, prior learning, etc.) will influence what emotions and behaviours we actually do display. For example, Bonobos and Chimps share a recent common ancestor, but one species is generally peaceful while the other is extremely violent (this is due to recent evolution). But whether an individual Bonobo or Chimp behaves peacefully or aggressively is also influenced by that individual’s learning and the situation (this is due to environmental factors).
Anyway, if you’re interested, you should try looking into human evolution and behaviour. It’s a pretty new field in biology (separate from anthropology) that investigates how human evolution might explain modern behaviour patterns. It’s interesting to look at humans as animals trapped by their evolutionary and personal histories, and it’s certainly changed how I see humanity.