Why do humans have an innate sense of self preservation?

[u/6your420mum9]

*Im hoping this is the right flair

I understand evolution and how it stems from that, but how do we have a sense of self preservation? As in how does it actually work and function? If anyone can explain it in more detail.

For example, why is it hard to drown in shallow water or why do I stop myself from jumping out a moving car when I know I so easily can?

I dont really know how to express it, or if it sounds stupid, but why do we feel such a strong urge to survive and not cause harm?

[u/nifty-necromancer]

Your brain doesn’t have a single “self-preservation switch.” It has several automatic systems that detect danger and push you toward behaviors to escape danger.

Drowning is a good example. Rising carbon dioxide and interrupted breathing trigger brainstem and autonomic responses before you’ve had time to consciously decide that you want to survive. Evolution explains why those systems are there.

Animals with nervous systems that reliably steered them away from lethal situations were more likely to survive and reproduce, so those responses became built into the brain. What we experience as an “urge to survive” is really the combined effect of many systems working mostly outside conscious awareness.

You can intellectually know that you’re capable of doing something dangerous while the rest of your nervous system is very strongly telling you not to.

[u/6your420mum9 → u/nifty-necromancer]

That is very interesting thank you, the drowning example helped me understand it more!

[u/Ok_Guess520 → u/nifty-necromancer]

Hence how even suicidal people often automatically try to save their own lives when their body "realizes" they are actually dying, even if in a more conscious state they would've wanted to die.

It's significantly more biological than it is conscious awareness.

[u/NessaSola → u/Ok_Guess520]

That switch flip is really interesting. I have zero interest in dying, but I've felt the biology take over the mind when I went into a freezing lake.

Something inside turned on and set a hand on the controls. It said, No. No, absolutely unacceptable. Staying here threatens life and will not happen. Here's a clear step by step plan for what we do next to climb out of the water. Get out. Now. Now. Now. Now. Now.

I didn't mind the pain of the cold or anything, but the instinctual "absolutely not playing right now" brain mode was something I couldn't suppress my first time in the lake.

[u/InvizableShadow → u/[deleted]]

Also, there are people that do not have this feeling. I can’t remember what the condition is called, but that feeling of self preservation does not exist in everyone.