>>5150501
Yes. Even things like termites aren't born with instructions how to build or layout a mound they just tunnel in response to the needs of the current situation but on larger scale this creates a kind of complexity that the termite itself doesn't possess. The spider doesn't really plan it just kind of responds to a need then that action requires another response and so on until it returns nothing and just waits.

>>5150501
It's 90%> "genetic" (instinctual)
Spiders can get better and weaving webs with age and experience. Also jumping spiders are the exception and they're pretty smart for what they are, given their lifestyle involving active hunting and thus problem solving,
https://www.youtube.com/watch?v=_QF6kaOAuYg

>there is really no reason to not assume that humans also have complex behaviors genetically written into them
That's a massive leap in logic. Human brains aren't limited by the same factors that limit spider brains. We have fight or flight instinct, don't get me wrong, but we don't have instinctual architecture for reasons that should be obvious.

>>5150501
even mice digging tunnels is genetically controlled

https://www.sciencedirect.com/science/article/abs/pii/S1084952116302397

>>5150501
Human behavior is also largely genetic but no one wants to have that conversation.

I would say "instinctual" genetics are largely gender specific in primates, or socially specific in humans.

>>5150501
Never quite understood how a species that is dependant on moisture to "smell" chemicals with its legs and solid objects to "see" vibrations evolved in a desert and the only adaption was losing two eyes. like, what?