Evolutionary Psychology of Suicide: Pain-Brain Theory Explained

Okay, so I'm on a college campus in the middle of summer. Um it's not even really August yet, but here we are. This

is my dorm. My roommate's out right now, so I decided I would just start recording. And today I want to talk

about the evolutionary aspects of suicide. So suicidal behavior should be a threat

to humanity as a species, since death ends all possibility of reproduction. So in theory, people shouldn't have the

ability to intentionally kill themselves, and suicide shouldn't have survived natural selection.

In this video, I'm going to explain why we've evolved an ability to commit suicide, and how self-killing fits in

the grand scheme of human evolution. I'm going to be using Cast Opera's framework to do this.

Cast Opera is an evolutionary psychologist. He currently holds the most promising theory for the

evolutionary origins of suicide. And I haven't seen too many videos on YouTube talking about it, so I wanted to make my

own educational video breaking down his work in layman's terms. To start with some background, as of

2024, over 700,000 people kill themselves annually. Which makes up around 1.5% of deaths. So

1.5% of people who die, die by suicide. Suicide is a public health issue globally, and it has been for tens of

thousands of years, ever since humans evolved both the intelligence and the biological defenses to actively live

with it. To understand the evolutionary origins of suicide, we first need to use the

pain brain theory to understand suicide as a mechanism. Essentially, our minds and bodies house

two elements which produce suicide. Those being pain and intelligence. I'm going to go into these two elements

in depth. The first element, pain, is a very important tool. It exists to alert an

organism of some condition which jeopardized its ancestors reproductive chances and by proxy is endangering the

current organism's chances. Let's say you step on a thorn. The pain of that would motivate you to

end that painful state. In this case, you'd probably remove the thorn from your skin to alleviate your

condition. Everyone's physical and even social pain is backed by our ancestors previous

suffering which has been forever stored in our genes. So, let's say the people who pulled the thorn out of their feet

tended to reproduce more successfully than those who kept walking and eventually crippled themselves.

This is an example of how pain has evolved as a protective mechanism. Nearly everyone has at least one last

resort method to ending pain. That last resort is suicide. Suicide is the inevitable byproduct of

painful tension. And by pain, that can vary from literal physical pain to psychosocial pain.

Our bodies demand that we do something to end pain or otherwise escape pain. That's what our ancestors and their

genes programmed us to do. And since you can't feel anything when you're dead, technically, death is a

method of ending your ability to feel bad. At first, this might seem

counterintuitive because most of the time dying sounds like the most painful thing ever.

Why would our bodies be programmed to end pain with, in a sense, more immediate pain?

Even if your mind is thinking long-term and and you realize that in the long run suicide would be an end to all forms of

pain, Logically, your body shouldn't be able to let you kill yourself in its efforts

to avoid pain. To explain how humans have this ability to commit suicide, I'm going to use an

example from the evolution of life worth living. The human organism is caught between

their phenotype and their genotype. The phenotype is the physical body, and the genotype is the genetic code of the

physical body. We'll treat these two things, phenotype and genotype, like characters in a play.

Phenotype and genotype need each other. Phenotype can't survive without genotype's operating instructions.

Genotype can't replicate its genes without phenotype's physical reproductive equipment.

Phenotype is the only one in this pair that can feel pain. So, at times, suicide has an absurd,

unrealistic appeal. Phenotype was unintentionally programmed this way by genotype.

On the other hand, suicide is disastrous for genotype because death ends all future prospects of

reproduction/replication. If there's no other method of ending unbearable physical or otherwise

psychological pain, the human organism must choose to obey either phenotype or genotype.

Obeying phenotype results in the organism's death. Obeying genotype results in a prolonged

suffering, but the continuation of living. Pain is a constant battle of biological

needs, and suicide functions as a pain-relieving mechanism. Before I proceed with the rest of the

video, I wanted to do a PSA of sorts. I know it's kind of obvious when my eyes

are reading from line to line, but bear with me. I want to get this right, and I did write it. It is

genuinely coming from me. Um and I want to get it right. So,

we're just going to start with that. Um I just wanted to ask that you don't use this video or any of my other content to

hurt yourself. I know as long as this is on YouTube, there will be a risk of

people doing that. And it's something I worry about because I know it's a thing.

I know that for however long this is going to be on the internet, there's a strong possibility that someone will

hurt themselves while watching this. The topic of this video is already a risk factor in it of itself.

And I really don't want it to be. I don't want this video to contribute to the permanent scarring on someone's body

or like the normalization of self-harm um within their minds.

That also applies to the other infographic on this channel, which talks about the neurobiology of suicide.

I know this might seem long and disclamatory Disclamatory's not a freaking word, but

we're going to use it here. I know this might seem long and disclamatory to some of you watching

this, but I felt it necessary to add this in the middle of my recordings. Um

I want these videos to be informational and possibly help some people understand why they exhibit certain behaviors.

If you're considering hurting yourself or doing it later today, sleep on it or wait until you're around

someone who can hold you accountable. And I know that doesn't mean [ __ ] but if this video is pushing you towards

that mindset, that state of mind, that behavior, please like feel free to click off and

do something to make yourself feel better. I now want to move on to the other

element of the pain brain theory which produces suicide. That being human intelligence.

If pain is the motivation, then intelligence is the means. There are three demographics who haven't

been known to commit suicide. Those being non-human animals, the severely intellectually disabled, and

children under the age of five or six. I want you to think of suicide as a cognitive challenge.

Very young children have no meaningful concept of death. And even as they age, it still takes

years for them to get the whole picture. As an adolescent, you would have needed to develop certain cognitive skills to

understand death. Like the ability to grasp its permanence, or the ability to mentally project forward and back in

time. And most importantly, you would have needed the ability to apply death to

yourself. You would have needed to have developed an understanding that death is

universal. And you too will die someday. Understanding suicide is a little

different. The ability to grasp suicide comes and goes at different stages of cognitive

maturation, or maturity. That is why, as you can see on this graph, there's a spike in adolescent

deaths by suicide. The surge at around age 10 indicates when the brightest become smart enough

to both conceive of their mortality and act on that knowledge, given that they have the painful motive to do so.

From that point onward, the curve reflects the different ages at which children in pain have gained the

intellectual means for suicide. The intellectual threshold for suicide is measured by orders of intentionality.

So, normally, your mind has two degrees of intentionality. The first being the contents of your own

mind, and the second being the contents of someone else's mind. As you can imagine, those degrees and

orders can pile up quick. For instance, I could be thinking about whether you know if Mary has asked Peter

to not tell James about the party. That's a very convoluted example, but you got the idea.

That sentence includes first, second, third, fourth, and fifth orders of intentionality.

In terms of suicide, if you are capable of the third or fourth order, then you're pretty much

capable of killing yourself. As you can see here, virtually everyone has capability for this first order of

thinking. I hurt. That's basic. That's animalistic. The second order of intentionality, in

terms of suicide, is the self-awareness of being hurt, rather than the feeling itself.

Suicide potential begins at the third order of intentionality, because it's the beginning of the search

to end that pain. It's being aware three times over. Fourth order of intentionality is more

of the realization that suicide is technically a method of ending pain. Don't get me wrong. This line of

reasoning is very delusional and misguided, but it's also what I believe to be the

thought process behind suicidal behavior. Again, if you have the cognitive skill

to grasp death in full, combined with the ability for third and fourth order thinking,

then you are fully capable of suicide. This is also why the three demographics I mentioned earlier,

non-human animals, the very young children of whatever our population, and the severely

intellectually disabled are protected populations from suicide, because

they don't have the skills necessary to think of it. So, that was the intellectual threshold

for suicide. I now want to go more into how a suicide originated in our evolution, since there

was a point where we weren't smart enough to think of suicide as a possibility for ourselves.

There's a concept called the fitness ceiling to explain how suicide evolved into a human mechanism.

And it's accompanied by a graph which I'll showcase in a bit. To understand the fitness ceiling and

the aforementioned graph, we first need to understand adaptation. Adaptation is a biological trait which

evolves by selection to solve a fitness problem in a species' evolutionary past. When I use the term fitness in that

statement, I'm not talking about physical fitness or exercise. I'm talking about how successfully a

species reproduces. Looking at this image, you can see that the brown beetles have more offspring

than the green ones because they've been doing a better job at surviving and [ __ ]

So, the brown beetles have a higher fitness, the green beetles have a lower fitness, etc. and so on.

At a point, certain adaptive traits lose their original survival advantage as they continually develop to the point of

exaggeration. So, there's a fitness ceiling for when a trait undermines its reproductive

benefits. So, in theory, when it came to suicide, humans had a fitness ceiling of

intelligence. Think of it like this. There's a usual variability of fitness traits which

creates a bell curve. This is to convey that some people used to be and are more intelligent than

others, just as some are less intelligent than others now. But, the spread is random and more or

less creates a normal distribution. Most people fall towards the middle, again, being more or less than average,

with a diminishing minority trailing off towards the high and low extremes. But at some point in our evolution,

being smart must have stopped being beneficial to our reproductive prospects.

Because intelligence in an animal, to our extent anyway, produces suicide. Basically, any animal that realized it

didn't have to suffer in pain would freaking jump at the opportunity to kill itself.

So, the fitness cost of being smarter should have stopped being worth paying. So, how have we surpassed this fitness

ceiling? To answer that question, I've got a graph for some visuals.

Here we have three miniature bell curves on different levels from each other. As you can see, the fitness ceiling of

intelligence is beginning to look more like a cliff. So, we'll call it the cliff edge of

suicide. Before we developed the anti-suicide defenses to actively survive with

self-killing as a possibility, if an organism went beyond the cliff edge, then their germline disappeared.

By the way, the anti-suicide defenses that I just mentioned are common mental disorders.

I covered that part of the theory in my last video, and I'll cover it again later in this one. But for now, bear

with me whenever I use the phrase anti-suicide defenses. If the bell curve is completely behind

the cliff, then the entire breeding population is well away from the edge, protecting the minorities in the

forward-facing tail by proxy. The only reason the forward-facing minorities would be protected like this

is because if they survive and reproduce, then their offspring will populate the main body of the bell

curve. Their reproductive success impacts the whole populace.

So, in some way, our ancestors must have come against the ceiling long enough for them to have

evolved anti-suicide adaptations, which made suicide, or at least the threat of suicide, generally survivable

for most of the species. So, how is this possible? Well, here's what might have happened.

Selection pushed early human intelligence close enough to the edge for where it was just survivable.

Human intelligence was then held there for many, many generations. Over these generations, the occasional

genetic mutation had an anti-suicide effect, which was spread all throughout the population.

On average, people didn't benefit from these adaptations. The average person was far from the

cliff edge, too far from the cliff edge to um enjoy it. But the minorities who were

around the cliff edge enjoyed the adaptations. And in consequence, they survived long

enough to reproduce. As cognizance beyond the threshold for suicide became more and more survivable,

the population's average intelligence rose. The bell curve was squeezed closer to the edge, and even more minorities

were pushed beyond the cliff's lush intellectual threshold. This elevated the need for more

anti-suicide adaptations, continuing the cycle for thousands of generations, thousands and thousands of times over,

until we ended up here. Although a steady percentage of us have consistently fallen victim to

self-killing, we're all equipped with anti-suicide defenses in our modern day

because of the generations which surpassed the cliff edge of suicide. All of this leads me to my next topic,

which is explaining and defining anti-suicide defenses. Self-killing has been a recurring

fitness hazard in human evolution, which we've evidently worked around. So, suicidality must be paired with an

adaptation, which just so happens to be common mental disorders. Disorders like depression, anxiety, schizophrenia,

substance abuse, etc. Although mental illness very much contributes to suicide rates and

psychic, the pain brain theory posits that common mental disorders originally evolved to prevent suicide.

They do this by either lessening pain or lessening the intelligence required to kill yourself.

According to Sopper, mental disorders are so specifically tailored towards a preventative function that they had to

have evolved to be anti-suicide defenses. As an analogy,

let's say you didn't know what an accordion is. Let's say I gave you one and I asked you

what it was made for. You'd probably see the keyboard and the shoulder strap

and you'd figure out that it was designed to make music. You can do something very similar with

biological features. For example, you could study the heart and quickly figure out that it's evolved

for pumping blood. There's no better explanation. So, I'm going to list a multitude of

reasons for why common mental disorders evolved as anti-suicide defenses. One is that we experience these

disorders because of some form of psychological pain, which is usually caused by problems in

our social lives. So, grief, abuse, isolation, stressors, failure, things like that.

Connecting to my next point, two is that mental disorders are origin blind.

It doesn't matter what type of psychological pain is experienced. Pain is pain and your body can't read

your specific thoughts like that. Although your consciousness is housed by the brain, the brain itself doesn't

communicate with a train of thought. It communicates via a neuroendocrine system of hormones, chemical messengers

which are emotion. Emotions have evolved as internal signals, which the central nervous

system uses to select the best behavior in a given situation, like fight or flight.

So, our brain isn't following the words and ideas we think in. It's like listening to music in a

language you don't know. You may not understand the lyrics, but you can understand the mood the song's

going for. In the same manner, the central nervous system, or nervous system in general,

has evolved to react to strong, long-lasting psychological pain as if it were a suicide threat.

That's why mental disorders are triggered regardless of suicidality. That's also why mental disorders are

pathological, which is my third point. Most people with mental disorders

suffering, but not suicidal, and later become suicidal the longer that they stay mentally ill.

The majority of mentally ill people aren't even suicidal, by the way. But, that only strengthens the argument

for mental disorders being both a self-killing preventative and an unintentional pathology.

The fourth reason disorders have a protective function relates to adolescence.

Just as suicides are virtually non-existent among very young children, common mental disorders are extremely

rare among kids below a certain age. In fact, the peak age for arrival of mental disorders is adolescence.

This aligns with the intellectual threshold for suicide, which happens to bring me to my fifth point. Mental

disorders either do something to lessen the pain or the intelligence needed for suicide,

fitting into the pain-brain theory. For example, depression, substance abuse, self-harm,

they all either do something to numb or redirect pain. Someone who's depressed may become so

numb, they won't have the motivation or the energy to get out of bed, let alone leave their house or kill themselves.

And for self-harm specifically, it doesn't have to be an active suicide attempt because most acts of self-harm

are just super bad coping mechanisms. I've used this example before, but I'll say it again. Non-suicidal self-harm is

just it's very commonly used to redirect pain. So, like, let's say you bite your

lip after stubbing your toe on something. By applying a secondary, unrelated

stimulus, you're directing feeling away from an even bigger pain. So, people with self-harm disorders try

to relieve their mental pain by inflicting um physical pain. It's a secondary

stimulus that takes attention away from whatever's going wrong psychologically. Um

as for the lessening of intelligence, mental disorders are notorious for debilitating cognitive functions.

Neurological studies of depression show that the brains of those impacted floods parts of itself with useless

information, causing processing to slow down. I'm bringing up depression a lot, but

it's one of, if not the most common mental disorder. So, most people who kill themselves have

it, and it does a number on both the pain and brain aspects of suicidality. Anyways, people with depression, eating

disorders, bipolar personality, schizophrenia, they all gain cognitive deficits,

struggling with things such as formation um and the retrieval of memories. Those are the most prevalent points

pointing towards common mental disorders having a suicide preventative design. I could keep going, but I think I hit

the high points on Cast Hopper's pain brain theory. So, I now want to move on to some

counter-arguments I've come across. To begin, there's a few statistical issues with the mental disorder defense

model. According to the pain brain theory, lower suicide rates must be accompanied

by higher rates of common mental disorders, i.e., anti-suicide defenses.

So, for example, let's say demographic A has a lower rate of suicide than demographic B.

This means demographic A must have a higher rate of anti-suicide defenses causing these lower suicide rates.

This doesn't align with real life. Looking at rates by gender, men have a higher rate of severe common mental

disorders than women, especially when including psychotic symptoms. However, these higher rates of disorders

aren't doing anything to lessen men's suicide rates. Women not only have lower rates of

anti-suicide defenses, but they also have a lower suicide rate than men. Um so, I didn't actually tailor those

previous bar charts to scale. I just needed to create something to better conceptualize what I'm talking

about. It's low-key lazy and embarrassing, and I'm not proud of it.

So, I do have some actual statistically accurate stats to prove my point, which you can see on screen.

It is generally known that men die to suicide more often than women. Granted, women are more likely to make

an attempt, but they tend to use lower lethality methods, which may be indicative of the

anti-suicide defenses messing with their cognitive functions. So, overall, they do die less often.

This is also very generally known in the fields of suicidology. Women make more attempts,

men die more often. Here's another chart demonstrating that men kill themselves more often than

women. And here's a chart that I made proving that men, empirically anyway, have a

higher rate of anti-suicide defenses at work than women on a global level.

All of these stats will be linked in the description. The bar in

dark blue was actually an average out of 56 to 69%. So, the difference between men and women may be even greater than

initially thought. So, this doesn't align with Cassorla's theory.

By his logic, because women have a lower rate of anti-suicide defenses than men, they should be dying more often than

men. Although women do have higher rates of depression, eating disorders, and

anxiety specifically, anxiety was excluded as an anti-suicide defense by Cassorla

under the assumption that it is its own separate origin. So, the point still stands.

According to the theory, women should be committing suicide more often than men. None of this completely negates the

anti-suicide defense model, but it does make it the least supported part of the theory.

This also raises the question as to how rates are reduced in women without the use of severe mental disorders.

This next critique is going to be a bit personal, but I have read a bunch of Cassorla's works, critiques of his work,

and at this point, I've done an unhealthy amount of research on suicide as a topic, so I do think my takes have

some objective value. So, keep watching. The pain brain theory posits that because anti-suicide defenses are super

costly to activate, I mean, they're literally mental disorders. Your body doesn't want that.

They're so costly to activate that they probably have defenses of their own called fenders.

So, basically, at a certain point, the book becomes all about how literally everything was formed by suicide in our

evolution and preventing it, including religion and happiness. That's why it's titled The Evolution of

Life Worth Living, Why We Choose to Live. I don't buy it.

But, I'll get into that in a bit. So, Soper argues that because we're the

only animals on Earth who had to have evolved our irrational species-specific happiness,

um it's all because of the fact that we have the intelligence for suicide.

The same goes for our belief in gods and general benev- benevolence. If we didn't, there'd be too much of a

of a risk of us committing suicide. Soper created this whole system for categories of our delusions and optimism

and spiritual beliefs. But, I don't believe that most things, that

many things, especially concepts as big as spirituality and happiness and love, were fully evolved from a threat of

suicide. I agree with everything else that he talks about. How suicide has a

pain-relieving function, how early humans survived to develop a greater intelligence by evolving anti-suicide

adaptations. But, I don't believe people have hobbies because they've evolved to prevent

mental disorders, which is something he argues for in chapter nine. Kasser claims that humans' biological

foundation for love is that we treat others the way we want to be treated. When people love someone

unconditionally, they're trying to love a projection of themselves. They want to believe there's a benign

higher order in the universe. Whether it be God or for atheists, unconditional love.

Paradoxically, this kind of treatment does create a benign order of sorts, just on a more human level.

I agree with this idea, but I don't agree that this desire for a benevolent outside force has evolved as

a survival strategy against suicide. I think those psychosocial phenomenons are far too complex to be watered down

as defense mechanisms against self-killing or microbehaviors inching us towards reproduction.

For my final critique, I'll be talking about arguments against evolutionary psychology as a whole.

One of the biggest criticisms of the field is that it gives way too much weight to natural selection.

Natural selection isn't the most prominent part of evolution, taking into account things like mutation,

recombination, and genetic drift. So, by that logic, a counterargument can be made that suicide doesn't need a

function or a mechanism because suicide is random, just as evolution at large is random.

Although I agree that a lot of evolutionary psychology puts way too much emphasis on natural selection, I

think suicide is way too specific in its process and mechanism to be random. I'd like to

Whoa. I'd like you to think of the accordion analogy again. Looking at the keys and strap on an

accordion, you can figure out that it's made for music.

Suicide requires a certain level of intelligence specific to human beings of a cognitive maturity at the threshold of

suicide as evidenced by a lack of deaths in the lacking demographics. Suicide is also always preceded by

suffering with death being a solution as it numbs pain.

It numbs any feeling or state of being that you could possibly be conscious of. What better explanation would there be

for self-killing? The body demands that you end pain to the point where last resorts are

expected to be in the realm of possibility. And evolutionary psychology may not be a

good lens to study things like religion or happiness through, but it is the only lens we have to study

suicide from an evolutionary standpoint anyway. Suicide is a mental phenomenon with a

very specific function, so it can be explained as a mechanism by using the field of evopsych. So, it does have

legitimacy. So, this has been the evolutionary aspects of suicide. If you watched

through the personal opinion section, I highly appreciate it. I've I've recorded so many

outros. I I don't really know what the [ __ ] I'm doing or what the [ __ ] to put here, but

I I really hope you enjoyed this video. Please read Cas Stopper's book. Um I highly recommend it. It's like I've said

a thousand times, it's called um The Evolution of Life Worth Living: Why We Choose to Live. I linked it in the

description as a PDF. It can help so many people. It has helped me um especially with like thinking in terms

of behavior. If you struggle with like some sort of mental illness or suicidality, this

not freaking book will. It It'll give you a different perspective at least. Maybe it it's not

good for everyone. It it is like it is morbid to like

study things like that while you are uh struggling with it. I'm not I might not necessarily be talking about myself,

but like I'm I'm not going to spill all my personal [ __ ] here. But yeah. Um

I'll be making more videos. Please ask me in the comments if you have any questions. I want to talk about this so

much more. I want I want to properly talk to people about this after they've watched it. I want

their opinions or if they've been confused about anything. I want to clarify myself. So please do that.