So the question to my mind is not how depression, which appears maladaptive, proves through secondary gains adaptive for the individual gene carrier. Rather how does the depression of the individual gene carrier contribute, not to his or her particular survival, but to the survival of the group as a whole?
Since I lack any scientific evidence for what I have to say I must engage in rampant speculation and attempt to imagine circumstances that suggest how depressed gene carriers might have been of benefit to the whole. And since about the only think I really know is me—and not very well even there—I imagine myself in Pre Historic Times. I am a very pasty white person and my knowledge of family genealogy suggests my particular genetic make up evolved in quite cold areas, like England, and possibly prior to that Denmark.
So I imagine a time and a world that, for certain periods of time was warm, and then for extended periods extremely cold. What was one to do on those days but to sit in one’s cave, eat bits of bark and insects possibly, while trying not to freeze to death? I think such circumstances might have depressed the hell out of anybody. But this is situational depression, not genetic. I am talking about the folks who are depressed even when it’s all warm and sunny.
One thing we know about depression today is that depressed people tend to lose their appetites and, in many cases, sleep way too much. The tendency to not eat and to sleep excessively seems to be in the circumstances as described quite adaptive for the individual gene carrier since in those cold months in the cave there was very little to eat and little to do but sleep.
Further these depressed people might have functioned for the whole as “role models.” Even the more active and non-depressed types might have located in the behavior of the depressed a way to endure their terrible circumstances. If I am not to go completely insane or stir crazy under these horrible circumstances perhaps I should mimic the behavior of my depressed colleagues who while perpetually miserable seem able to endure terrible circumstances.
The non depressed person, one knowing hope, might then have adapted the behavior of the depressed knowing that this too will pass and the sun will shine again. The depressed persons would lack this consolation—that the sun will one day come out again and there will be plenty of berries and flightless birds to eat—and think, yes, this too will pass…when I die. That for the depressed would seem to be the only end in sight and death one might say really is maladaptive.
I therefore conclude that the depressed, lying around moaning and groaning, began to try to imagine reasons for their maladaptive selves and so became the first philosophers and religious figures. Why did this terrible thing happen? Why did my infant die at birth or my spouse for no apparent reason? Well, you know…the gods did it. Thus the depressed became the first ideologues; people desperate to explain and somehow understand the unmitigated horror of their condition. In which case, I believe I can claim, that the depressed contributed mightily to the survival of the whole, and I say this without fear of contradiction because there is no way to prove me wrong, and for that matter to prove—thinking of those pseudo scientists—that individual gene carriers in Pre Historic times were ever depressed.