What about suicide in other species?
It’s a common misconception that humans are the only species that kill themselves. This is definitely not the case. However, suicide in other species is more like self-sacrifice
Fire ants: mate in-flight, and the male’s reproductive organ literally explodes in the female, at which point he promptly dies.
Honeybees males die in circumstances almost identical to those above, except that some male bees survive because their abdomen doesn’t always explode.
Pea aphids, Australian redback spiders, mantises, and worker bumblebees all engage in self-sacrifice too, either in mating or dying for the good of the colony. Of course, these are insects or arachnids, not very close to humans in the evolutionary sense.
Male lions Often sacrifice in battles with males of other prides who are trying to win females. Interestingly, even males who have NOT mated will die for females, presumably because the males who have mated are often their genetic brothers. This is reminiscent to Joiner (and to me) of humans who die in war.
Rhesus monkeys have been found to self-injure by biting or clawing at themselves when severely distresses, often in the same body parts that humans do. While they don’t kill themselves, this is what some researchers call parasuicidal behavior.
Obviously this is not the same as most suicide in humans, but you can see the similarities. In each case, evolution has performed a cost-benefit analysis. Perhaps human suicide may be partially due to some misfiring evolutionary mechanism that we don’t yet understand.
8/30/2011: MYTH: Lemmings kill themselves. From wikipedia – “Lemmings became the subject of a popular misconception that they commit mass suicide when they migrate. Actually, it is not a mass suicide but the result of their migratory behavior. Driven by strong biological urges, some species of lemmings may migrate in large groups when population density becomes too great. Lemmings can swim and may choose to cross a body of water in search of a new habitat. In such cases, many may drown if the body of water is so wide as to stretch their physical capability to the limit. This fact combined with the unexplained fluctuations in the population of Norwegian lemmings gave rise to the misconception.”