system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come most of the time we do things like blink and breathe subconsciously but we can also control them consciously?
gpt
This is a good question, but hard to answer definitively. Regarding blinking, it can be a reflex, like when you get something in your eye (autonomic); or conscious, say you walk in on your mum naked (conscious). The autonomic type is a lot quicker, as it's a reflex.

Breathing on the other hand is controlled by your brain stem (among other areas), but you need conscious control over that. For instance, say there is a foul, potentially toxic smell, and you decide to hold your breath to prevent injury or death. This was probably evolved through natural selection.