Firefighter here. I was reflecting on a fatality I attended recently. My thoughts wandered to how a body looks like it is ‘just matter’ in a way that a living thing does not, even when sleeping. Previously I assumed this observation was just something to do with traumatic death, but this person seemed to have died peacefully and the same, ‘absence’ of something was obvious.
I’m not a religious person, but it made me wonder if there actually is something that ‘leaves’ when someone dies (beyond the obvious breathing, pulse etc).
I’m not looking for a ‘my holy book says’, kind of discussion here, but rather a reflection on the direct, lived experiences of people who see death regularly.
It’s just a living body makes so many minute movements we don’t usually notice.
Lungs Expanding and contracting, flow of blood (yeah you can notice that), texture of the skin, muscle position, etc.
We have evolved to quickly differentiate between a living body and dead body. That’s why the uncanny valley exists.
Interesting. Any thoughts on what evolutionary advantage there is for being able to sense whether someone is alive or not?
I seem to recall that animals can sense whether other animals are dead (or rotten/contaminated)?
Imagine coming upon a lot of delicious-looking mushrooms, a couple of which are in the hands and mouth of a dead person. Being faster to realize the person is dead, and to flee, than the time it takes to take and eat the mushrooms, is why you’ll live to reproduce. Same for the dead animals around that fresh-looking water hole.
Thank you for ELI5!
I don’t think there’s any great mystery to this. We want to breed with the mate most likely to help us produce viable offspring. Therefore we’re sensitive to indications of health and good genes. Symmetry, smoothness of muscle movements, quality of skin & hair, indications of good blood flow, even things like regular breathing are all indications. When we see a simulation that appears not quite human it’s noticable for all those details. That detection of unhealthy can easily detect death of course. There may also have been an instinct to avoid the sick, but social pressures override that sometimes.
The internet theory that we wanted to detect imposter humans is silly. Early hominids interbred a lot. It’s not “human” that we’re sensitive too. Just health.
They smell putrefaction.
It starts immediately when life has ended. It doesn’t wait for days, or hours, out of decency or so…
TIL the word “purification”. Thank you!
Edit: putrification (damn autocorrect, and it’s still underlined in red).
Edit: putrefaction (sigh)
I admire your tenacity.
That’s where “putrid,” mostly used ime to describe a rotten smell, but also applicable to the morals of your least favorite politician, comes from
I love this question! I’ve seen it asked a few different ways. “What evolutionary benefit did the recoil reaction to the ‘uncanny valley’ provide?”. Thinking about the answer is kinda scary.
I’d think one benefit of being able to quickly discern between the living and the dead would be increased survival chances during death events. If you can see that someone is dead, less likely to face a dangerous predator, natural disaster, or contagion, or at least stop investing precious time in those situations if they found themselves in them.
I think it’s mostly for things like rabies or other contagious diseases that make people act differently. That’s mostly because frankly, I don’t get nearly as much of a reaction to an unanimated but lifelike robot/mannequin/sex doll/CGI screenshot as I do to a moving one, and I wouldn’t describe my reaction to a dead body as uncanny valley at all. That said, it was a loved one’s body and I watched them die peacefully, so that could reduce any unnerving aspects.
I’ve heard the uncanny valley affect also being attributed to ancient ancestors encountering other early non-human-but similar competitors. The effect of, “Oh look, another Neanderthal- Wait, shit, not like me, abort abort!”. I don’t know how likely that is, but it’s an interesting thought.
Early hominids interbred. Modern humans are a result of that mixing.
I’m not an expert on this at all, but my understanding is that “evolutionary advantage” is a misconception. Mutations don’t have a goal, and they don’t always provide an advantage. Hopefully someone smarter than me can explain better.
Edit: spelling
Evolution throws spaghetti at the wall and anything that sticks it keeps. Usually stuff sticks because it’s useful in some way, but some stuff sticks just because of random chance.
For example if a few individuals colonize a new location, then whatever genes those founders have will be prevalent in the new population. The classic example is the deaf people on Martha’s Vineyard. Some of the original settlers of the island were deaf and passed that down to their descendants.
The smaller a population is the more it’s affected by random genetic drift. (It’s easier for a gene to randomly spread to an entire population if the population is small.) The larger it is the more it’s affected by natural selection.
I have to admit I have wondered if it is the blue skin.