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Is suicide a biological misfiring or defect?

  1. Jul 8, 2018 #1
    The more I learn about biology and human nature, the less sense contemplated and executed suicide makes. Especially non religous.

    What accounts for suicides concidering we are supposed to be hard-wired to survive at all costs, and are equipped with instincts to accomodate that goal?
    Last edited: Jul 8, 2018
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  3. Jul 8, 2018 #2


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    What makes you think this is remotely true? Have you heard of the Darwin awards?

    If anything, we’re hard wired to reproduce, not survive (even that is an incredibly simplified view of evolutionary theory). If a suicidal tendency is inheritable (many forms of mental illness seem to be at least somewhat tied to genetics), that tendency will persist as long as the suicidal person is able to survive long enough to pass on those genes. There is a smattering of work that suggests that mental illness might somehow confer an evolutionary advantage, but the field of evolutionary psychology is still in its infancy.
  4. Jul 8, 2018 #3
    Suicide does not need to be caused by mental ilness. There are contemplated suicides by perfectly healthy individuals who saw no reason to function further and cancelled themselves out. These people did not derive joy from existing, but it makes them in no way mentally ill for holding that sentiment.
  5. Jul 8, 2018 #4
    Innate fears and suspicions of new stimulus, in particular sudden sounds, that could only be in place out of a neurotic desire to prolong living. It stems back to when early man escaped animals in the savannah.
  6. Jul 8, 2018 #5
    Suicide by non parents undermines that prospect somewhat.
  7. Jul 8, 2018 #6

    jim mcnamara

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    If you are a non-parent, then you are out of the evolutionary "loop" so to speak. Your presence can affect others who will potentially reproduce. Plus you cannot ascribe direction, intent, or end point to evolution.
  8. Jul 8, 2018 #7
    One is not out of the evolutionary loop by virtue of not reproducing yet. An innate desire to not reproduce, however, is equally flabbergasting as those who commit suicide. Neither one makes sense biologically.
  9. Jul 8, 2018 #8

    jim mcnamara

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    IMO, you are making up tenets of evolution based on your personal feelings. Which is completely understandable. It is simply not what these forums are about.

    You may be unaware of this:
    You are actually confronting the fact that humans are hypersocial. This trait evolved when we roamed around looking for food and shelter. There was strong selection pressure for group behaviors and cooperation.

    This human trait has "problems" for us as densely urbanized humans nowadays. You are seeing one of the issues.

    E O Wilson's 'The Social Conquest of Earth' is exactly what you are trying to deal with.
    Please consider reading it.

    Please cite references from standard biology textbooks or papers. Not opinions, not speculation. PF is meant for education, not speculation.
  10. Jul 8, 2018 #9
    None of the points I made can be proven, only inferred (which is true of large parts of evolutionary theories). If you are interested in in the topic of human nature and survival, The God Delusion by Richard Dakwins has an excellent passage on how our suspicions of foreign sounds is tied to our survival instincts way back in the savannah
  11. Jul 8, 2018 #10


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    Many different reasons.

    I have knew two people who committed suicide. They did it for what I would call rational reasons: avoiding extreme pain from non-treatable medical problems and not wanting to be a burden on others. These are reasons that to me just make sense.

    I knew another person who committed suicide who was emotionally troubled and at the same time was having problems with getting through his PhD. This guy could have been helped, perhaps, through his issues, but it didn't happen.
    Also in this class, someone down the road from me recently committed suicide. Word was (I did not know her) she had a failed relationship. May have been depressed. inter vention might have helped her.
    One might consider this a malfunction of the brain (clinical depression?). Like any other disease this would be something that has not been not overcome by evolution. This is a case of things not working right. This happens and evolution can't fix everything. Sometimes these kind of causes are treatable.

    Some people commit suicide for religious/political reasons: terrorists, political protesters (such as self-immolation by Buddhist monks) and such. These I would say do so for the reasons the hyposocial reasons described by @jim mcnamara. This over-rules any biological survival issues.

    It would be much more useful (IMHO) if you were to cite concrete examples for what you are talking able. Many specific cases almost explain themselves.
  12. Jul 8, 2018 #11


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    My point was that heritability of a trait is what causes its persistence in a population. Suicide is not exclusively caused by mental illness, but they do have a strong association, and we have evidence that mental illness is at least somewhat heritable.
    It stems back much further than that. But most of these fears can be socialized or habituated away. Even horses can be trained to charge into battle. The self-preservation instinct is pretty heavily targeted for conditioning during military training.

    But this brings up a different point. Aversion to suicide is not instinctive or reflexive like aversion to a loud noise is. Foresight of one’s own death requires a much more sophisticated thought process, one that humans don’t even develop until they’re ~10 years old or so. Thus why @jim mcnamara and others keep harping on the social aspect of suicide.
    You ignored my parenthetical remark. Sexual behavior is also highly socialized. And besides, not all high-fitness organisms reproduce. Google “genetic drift.”

    More to the point, applying evolutionary thinking to individual organisms is fraught with problems, especially in trying to explain social behaviors. Evolution is a numbers game. The importance of individual cases should not be overestimated. Are there genetically heritable causes of suicide? Almost certainly, but they either are easily generated sui generis in the course of random genetic drift, and/or they confer no distinct disadvantage to reproductive fitness that would eliminate them from the gene pool on the observed human timescale.
  13. Jul 9, 2018 #12


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    To the OP: On the evolutionary "logic".

    Evolution is not a "deductively logical" process that means all organisms behave perfectly rational. En element of irrationality (or variation) is necessary ingredient in evolution. So the fact that individual organisms seem to behave irrational from the perspective of another observer, is i not way in conflice with the ideas of evolution. Evolution is rather i think fundamentally random and having no "hard" rationality, the apparenty rationality is only a result of evolution and selection itself. On average, fitness traits is SELECTED, and become dominant in population, but it does not mean individuals are like deductive machines that make perfect decisions all the time, or are free from deviations.

    As for the "intrapsychic logic" behind drastic things like suicide its been mentioned already, it can be a way to achieve relief from extreme states of anxiety or pain, or i am sure there are also cases where suicides are due to impulsivity or psychotic conditions.

    What seems "rational" from the subjective intrapsychic perspective, may seem irrational from the population perspective. But a contradiction that appears when you inappropriately compare different "perspectives" is, quite similar to the observer dependent "subjectivity" in physical law, if you ponder about unification in terms of evolution of law.

    This is actually the primary reason why i as a physicist happens to have a sincere interest also in neuroscience and biological psychology. I see many are man strong parallells between attemtps of unifying models of personality psychology and unifying laws of physics. What makes this extra interesting is that there is quite a different in complexity between a subatomic particle (and its behaviour) and a human brain (and its behaviour). I think the fact that one can see clear similar abstractions may tells us something about how nature organises itself. Even from the point of view of a physicists, a human brain is nothing else but a extremely complex physical systems, and will follow the same principal laws of physics as the hydrogen atom.

  14. Jul 9, 2018 #13
    This is not about rationality, it's about fundamental instincts. That is, something far deeper than reasoning processes.

    Perhaps this will put it in perspective for you; If you are programmed to shun X and seek Y, and the opposite is in effect, then surely this needs to be accounted for. In the cases where mental ilness is not in effect, biology is left dumbfounded how this anti-instinctive behavior could arrise.
  15. Jul 9, 2018 #14
    But most people just not 'programmed'. There are some common 'habits' - I would not dare to call them 'instinct' since that word has a really exactly defined meaning what just does not really apply well to humans - but no real instincts (for adults).

    The connection between the genetic evolution and our habits in general is a difficult and not really clear thing. Hard to study and has some pitfalls what leads towards some dark thoughts suppressed under history.

    There are plenty who thinks that the whole social and conscient/intelligent stuff as 'cultural evolution' actually works as a playground for a different level of evolution: faster, more rapid and thorough than the old style genetic one. This is even harder (and less clear) area to research than the genetic evolution, but there are some results what worth some pondering over since it seems to have an affect on the genetic evolution: for example adaptation to new food sources what emerged on cultural base (lactose and such), but some even account some genetic changes on the success of cities.

    It might be useful to you to check some sources on 'group selection' too. Controversial subject, but brings many thoughts what makes more sense than trying to account everything blindly on genes.
  16. Jul 9, 2018 #15


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    Most of human behaviour can be thought of as spandrels.
    Large brain increases fitness, for one reason or another, so it is selected for. That it also can make you feel enough ennui to want to go alone into the cold, dark night is just a by-product of having that desirable trait.
    As long as the spandrels don't have sufficiently detrimental effect on fitness in a population, the adaptive trait will keep being selected for.
  17. Jul 9, 2018 #16
    Where did you get that we are "hard-wired to survive at all costs"? this isn't biology
  18. Jul 9, 2018 #17
    At all costs was hyperbole. Certainly beyond feeling moody about life, which a surprising amount of suicides are based on.
  19. Jul 9, 2018 #18


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    In the bigger abstraction i talk about, you can actually understand an instinct as an evolved "way of signalprocessing". And this signalprocessing is also in the abstraction level analogous to an abductive reasoning process. Lifeforms tries to find patterns and rules that help predict the future in a way that helps it survive. Note that with "reasoning" here i do NOT refer to reasoning taking place in a BRAIN, I am just talking of the abstraction of processes that takes place in physical systems nature.

    Also give the importance of variation, and that optimal traits are environment dependent, i don't see the mystery in how people somtimes comitt suicide. Its not like most people do it.

    Also the "survival selection" lies at a much larger scale. If you look at population level, not on individual level. To see explanations on population level is one thing, but to seek explanations on individual level (intrapsychic) is another thing. the explanatory mechanisms are different. It is similar to the different energy scales, in physical law. The laws for low energy domain does not explain the high energy rules, and also vice versa is a problem if the difference in complexity is too large - the possible link is lost in a chaotical system. So evolutionary explanations are still needed to link scales.

    Edit: To bring another analogy in to explain my way of thinking about this. To expect individuals to perfectly obey the rules that on average are expecte on the "average" in a population, is a similar fallacy to expect that emergent low energy symmetries must hold at higher energies.

    Last edited: Jul 9, 2018
  20. Jul 10, 2018 #19


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    Thread closed due to a lack of understanding the key drivers of suicide. So much of what has been said by the OP is just plain wrong.

    I see no peer-reviewed references to support any of the OPs conjectures and so the thread is now closed.

    Suicide is a serious and sensitive topic, I'm sure there are members of PF who have been deeply affected by it and who will be seriously hurt when they view the misinformation presented here.

    For those PF members interested in more information about suicide, I refer them to this website:


    and there are many more online websites with sound advice.


    If you have a loved one that you fear may be vulnerable then you should read up on suicide to learn the symptom and help them before its too late.

    My Dad once told me a story about a psychiatrist who was seeing a troubled patient struggling with personal demons. One day the patient shows up completely happy and apparently cured. The psychiatrist was perplexed but couldn't get to the bottom of the "cure". Later that week, he learned the patient had committed suicide and it was then he realized that the patients had decided that suicide was the answer and the struggle was over.

    Everyone please take care,


    Closing this thread...
    Last edited: Jul 10, 2018
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