Oriphiel

Warning, TL;DR ahead! Continue at your own peril.

I have to pose a question. If we exist purely to survive and make babies, why do people commit suicide? You're right, people (like all animals) do basically exist to survive and reproduce, but it's a bit more complicated then that. Our brains are more developed than most other creatures, and we have a deeper idea of what "survival" is. Basically, we have different tiers of wants and needs, and each tier has the ability to overpower the other.

It's not enough for humans to just survive and make babies, we also have social needs and desires (which is why most of us are posting on this forum). Being social creatures that developed to survive in groups, we have a desire to belong to like-minded factions. And when that "social survival" is threatened, we may even go so far as to take our own lives (which is spitting in the face of the biological imperative, and the drive to survive) to restore our standing (seppuku), end the criticism or shaming (someone does something "bad", and everyone rejects and shames them), or otherwise take the course of action that our complicated brains think are best (in cases where it might just be depression and internal factors over external that convinces us to do it, or a mix of both).

Humans want to survive physically, in the literal and original sense. This is the first tier that humans want to make progress in. Basically, humans want to have basic things like food and shelter, and they generally don't care as much about their social needs until these physical needs are met. And if our social network suddenly gets thrown out of the window (like if the world underwent a near apocalyptic event, and you were trying to survive in the immediate aftermath, scavenging for food and avoiding people, who might have bad intentions), we go back to this first tier.

However, once we have those basic needs, we start to want more. Humans are more likely to survive in a pack, and meeting other people and forming a group also increases our chances of finding a mate. Having the basic tools of survival at our disposal is well and good, but now we want to be distinguished in a faction (or at least follow an archetype of established behavior that makes us beyond social reproach, i.e. wearing clothing we know our friends will like, having a job that isn't considered embarrassing, etc.)

The last tier is reserved for grand ideas and abstractions that creatures without developed brains quite frankly don't give a fuck about. It's social survival and the need to belong, but on a much wider scale. This is where things like legacy and religion come into play, where humans desire to have an impact after their physical forms have deteriorated. Once people have fulfilled their physical and social needs, this is the next step towards giving them satisfaction with their existence. People form and share complicated ideas, usually ones that can't easily observed by an average person (for example, the belief that the universe has a god, the belief that the universe has no god, the belief that the universe is all just a dream in The Batlord's head, etc.). It almost exclusively runs on faith; a congregation believing their pastor, a group of students believing teachers and scientists, and so on.

Basically, everything we do is to attain homeostasis, not reproduce. Even though homeostasis and survival exist to be a foundation from which to reproduce, it's important to remember the distinction, because the drive to attain homeostasis can overpower the need to reproduce (like someone joining a cult that demonizes sex and babies, wishing for human extinction, to fulfill their social needs). And when the needs of one tier start to get fucked around with, they can overpower the others in an attempt to reattain balance, which is usually when people do normally illogical things (like kill others for their religion, kill themselves for a variety of reasons, etc.) to protect their social, religious, and physical ideals. For more information about the general idea of humans having tiered wants and needs, check out Maslow's hierarchy sometime: Maslow's hierarchy of needs - Wikipedia, the free encyclopedia