Evolution provides some ways of understanding depression’s origins and impact. Most everyone has heard of “fight or flight” as an explanation for anxiety. It reflects the fact that animals when faced with danger either prepare to fight the thing that threatens them or run away from the thing that threatens.
In this way, animals are better able to survive against their enemies.
Humans face challenges different from animals out in the wild. They cannot typically fight what threatens them or run away from something causing them distress. If you feel threatened by something at work, you can’t just start a fight with your boss or run away from your job.
No Option To Run Away From Problems
Anxiety in humans develops because they are often stuck with not being able to do what they most naturally want to do. So, an employee who can’t run away or start a fight with her or his boss starts to worry because of being unable to respond how he or she most naturally wants to respond. Evolution led to animals wanting to run away or fight when facing challenges so having to find another option causes symptoms of anxiety. How long that anxiety lasts depends on how long it takes for the person to decide on and use another option.
“Fight or flight” describes how a mechanism that helps with survival in animals impacts humans when they cannot respond that way. It shows how an evolutionary process can cause difficulties for humans when they do not find alternative ways of dealing with threats.
Anxiety, as a biological process, is rather easy to understand when the thought of in terms of “fight or flight”. There actually is a similar survival instinct in animals that helps to explain depression. It is called “social competition theory”.
Animals often fight to achieve some level of dominance in their group. Hierarchies are important for many animal species and being higher up in a group hierarchy can represent opportunities for more food, better access to resources, and, most important for evolution, more opportunities to reproduce.
Fighting for a higher spot in your group presents a lot of opportunities for animals. But it also presents a lot of dangers. “Fight to the death” is not just a cliché with many animal species but often represents a real way that conflicts are decided. An animal who decides to challenge another animal for a higher spot in a group runs a real chance of getting hurt in the process.
So, in order for an animal to survive, “giving up” in a fight can be a really useful strategy. If an animal thinks that a potential opponent could seriously hurt them in a fight, it is in their best interest to show as clearly as possible that they are not challenging their potential opponent. All sorts of signals, including lowering the head and backing away, show clearly to one animal when another animal has no interest in having any sort of competition. In this way, the outcome of a challenge is decided without either of the animals having any risk of being harmed or killed.
Certainly, one way to look at this is that this response to “social competition” prevents one animal from facing serious harm or death when facing an opponent she or he sees as stronger or otherwise likely to win a competition. But it also relates to animals not wasting energy in challenges at which they are not likely to succeed.
“Giving up” in situations where an individual is not likely to succeed is known as “learned helplessness”. Animals show “learned helplessness” in situations where challenges are insurmountable (or at least seem insurmountable to the animal). This could include situations where animals feel pain or discomfort in settings they cannot escape.
Very often animals caught in these situations will eventually stop trying to leave and will just stop and not move. They very much make clear that they have “given up” in these situations. “Giving up” is preferable to wasting energy or other resources trying to escape a situation that the animal perceives cannot be escaped.