Evolution of Suicide

I recently came across an article in the Guardian by Jane Powell about male suicide rates.  Specifically, Powell noted that of the 51,401 suicides in England and Wales from 2001-2011, 38,621 of them were of males over the age of 15.

Jaw-dropping statistics like that are sobering, and reveal that suicide really is a “gender issue.”  Throughout the article she explains why she thinks this is the case:

“Poverty and mental health issues affect both genders. The variable factor is culture and society; how we expect men to act, and how they feel they can behave. Suicide prevention work must, therefore, address this. Men, regardless of age group, often don’t recognise when they are depressed. Depression in men is likely to be signalled by anger, so won’t be recognised either by men themselves or by women as depression. Ironically, they may end up in jail rather than a GP’s surgery. For a man to ask for help is seen as failure, because by convention men are supposed to be in control at all times.”

— Jane Powell

As a male, I didn’t really know what to think of Powell’s explanation.  Are men committing suicide at dramatically higher rates just because of stereotypically-masculine social norms?  After analyzing my own psychology, I became more conflicted.  I believe I am a male with a relatively high emotional intelligence; does that mean I am at lower risk for committing suicide in the future? For some reason I became skeptical that it was that simple.

Powell isn’t the first person to realize that males commit suicide at higher rates than females.  In the 19th century, sociology pioneer Émile Durkheim discovered that males (especially middle-aged unmarried males) committed suicide at much higher rates than females.  If these trends have been consistent over time, and across populations, I started to wonder if evolution had any answers to this suicide disparity.

Among evolutionary scientists suicide is an extremely complicated and controversial topic.  Not only is suicide difficult to study, it also appears to contradict basic evolutionary theory.  If evolutionary processes program organisms to survive and reproduce, how could something as detrimental as suicide be selected for?

Some theorists believe they have solved this issue by applying suicide to concepts of inclusive fitness.  In highly social organisms, suicide should become adaptive when future reproductive potential is low and continued existence is a detriment to the reproductive success of close kin.  This theory, first proposed by Denys deCatanzaro, is still championed by some evolutionary biologists today.  But is there evidence for it?  And can it tell us anything about high rates of male suicide in contemporary times?

There is some evidence that highly social animals like bees commit suicide.  Whenever a bee stings another organism, it tries to pull its stinger out and fly away.  However, as a result it ends up pulling out its innards and dies.  Also, when a bee is parasitized by conopoid flies, they abandon their colony and fly off into isolation to die.  In both cases, deCatanzaro’s theory of suicide seems to be supported.  The bee is protecting the hive from predators and a disease outbreak, and by extension, its own genes.  But are these examples of suicide?  And do they have any relevance to human behaviour?

In order to find out, it is best to look at the data collected from non-human primate researchers.  Although no specific study has been conducted, there has never been a confirmed case of non-human primate suicide.  In certain stressful, artificial environments (e.g., biomedical laboratories, zoos, etc.) there are documented cases of self-injurious behaviour (SIB).  However, no primate has ever engaged in self-inflicted lethal displays. As psychologist Jesse Bering stated:

“There are no cases in which a chimpanzee has been observed to climb the highest branch it could find—and jump.”

— Jesse Bering

This is a big blow to evolutionary theories that claim suicide is adaptive.  If deCatanzaro’s hypothesis is correct, there are a number of highly social primates that should have suicide rates.  To me, this evidence seems to suggest that what we observe in highly social animals like bees isn’t analogous to human suicide.  After all, the examples of bee suicide seem to be more suitably compared to a human dying for a nation-state in combat, or voluntarily quarantining him/herself after contracting a deadly disease.

Another theory that I think comes closer to explaining the origins of human suicide proposes that suicide acts as a social red flag.  This theory proposes that suicide is a by-product of selected deep sadness.  If this theory is correct we should expect the attempted suicide rate to be higher than the suicide rate, and we should also expect kin-support after a suicide attempt to be significantly higher than normal.  Interestingly, this theory is overwhelmingly supported by data collected over the past decade.  Attempted suicide is much more frequent than “successful” suicide.  And after a suicide attempt many close kin usually do step in and try and make that individuals life better.

But what about the gender issue?  If suicide is an evolutionary by-product of deep sadness acting as a red flag for close kin’s support, why do we see suicide gender differences in contemporary times?

Interestingly, Powell’s initial assessment may be right; culture seems to play a massive role in determining gender differences in suicide rate.  This can best be illustrated by the fact that males have a high suicide rate in western countries, but in some areas of the world (e.g., China, Afghanistan) female suicide rate is higher.  Also, females typically attempt suicide at the same rate as males, but are less “successful.”  This could be because males typically attempt suicide through more effective violent means (e.g, guns, knives, etc.), whereas females typically attempt by overdosing on medications.

This may mean that the current high rate of male suicide in the western world, could be reduced through culture.  As Powell noted, men that seek help in western society are currently seen as failures.  If I am any indication, I hope that this type of masculine social conditioning is deteriorating.  I know that I personally have no problem seeking help (medical or otherwise) if I need it, and I try and surround myself with a positive support network that I can lean on when I’m down.  I do not feel any weaker or “less of a man” because I can discuss my emotions and feelings.  I hope that other men can adopt this perspective.  If they do, perhaps suicide will cease to be a gender issue in the western world during my lifetime.

Evolution has provided us with massive brains.  More so than any other animal, we are aware that we are alive.  Consequently, we are also more aware than any other animal that we can end our own lives.  However, we should be thankful that current data seem to indicate that suicide itself is not adaptive; it seems to be a last resort effort for us to reach out for help.  It also seems promising that males are not biologically destined to always suffer from higher rates of suicide.  With that knowledge, it makes it all the more imperative that we create a culture that is open and mature enough for both sexes to feel comfortable discussing emotions and feelings.  Nobody should be made to feel inadequate for feeling depressed.  Suicide is a serious issue, and I think the current gender disparity in suicide rates demands more attention from all of us.

You should probably follow Cadell Last on Twitter.

Also posted via Svbtle:


About Cadell Last
Hello. I'm probably drinking coffee and reading.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: