Darwinian Psychology and Depression: The Gender Differential Hypothesis

According to the American Psychological Association (APA), depression is a serious medical condition that affects how one thinks, feels, and acts. Symptoms of depression include feeling sad, loss of interest, changes in appetite, loss of energy, feelings of hopelessness and/or worthlessness, and thoughts of death or suicide. Depression is most commonly seen as maladaptive, and is classified as a mental disorder in the DSM IV.

However, adaptationist arguments for depression are rapidly gaining popularity. In this paper, I am going to discuss different adaptationist views of depression, with a particular focus on the Social Navigation Hypothesis (SNH). The SNH is one of the most well-known adaptationist views of depression, however; the SNH neglects to discuss the staggering rates of depression seen between men and women. According to the APA, the lifetime risk for major depression is 10 to 25 percent in women versus a mere 5 to 12 percent in men. In this paper, I will introduce the Gender Differential Hypothesis (GDH). The GDH is an expansion to the SNH that was designed specifically to account for the opposing rates of depression between genders.

Finally, I will end by discussing different treatment options for depression that align with most adaptationist views. The treatment plan I propose emphasizes the importance of both psychotherapy and medication in the treatment of depression.

Depression: Maladaptation or Adaptation?

There are many factors that are thought to be involved with depression. These include neuroanatomical differences, issues with regulating brain chemistry, hormones, and genetic factors. However, the overarching “cause” for depression is still relatively unknown — at least from a maladaptationist standpoint.

Darwinian psychology and adaptationist hypotheses seek to provide more detailed answers to these unknown questions by identifying ways that depression could yield net benefits to the depressed. In other words, in order to look at depression from an evolutionary standpoint, it is crucial to view depression as an adaptation rather than a maladaptation. It should be noted that there are also evolutionary arguments that conform to the maladaptive byproduct hypothesis. These arguments claim that depression could have evolved indirectly by pleiotropy — through a gene that codes and controls the phenotype of multiple unrelated traits. Hagop S. Akiskal, an American psychiatrist wrote about depression as a maladaptive byproduct in his 2001 paper titled: Dysthymia and Cyclothymia in Psychiatric Practice a Century after Kraepelin. Akiskal claimed that depression is merely a byproduct of a human adaptation for sensitivity to suffering. The maladaptive byproduct hypothesis should not be considered invalid or unsound, however; it raises some issues. The maladaptive byproduct hypothesis is extremely hard to test, and there is no concrete evidence regarding linkage of genetic traits. Further discussion of the maladaptive byproduct hypothesis or pleiotropy would be best directed towards a geneticist or genetic researcher. For our purposes, it is best to move forward viewing depression as an evolutionary adaptation.

A History of Adaptationist Hypotheses

The first adaptationist view of depression came around in 1934 by Aubrey Lewis, a professor of psychiatry at the Institute of Psychiatry in London. Lewis saw depression as a “cry for help” — an idea that was later built upon by many defending depression and evolutionary psychology. Lewis’ work marked the important beginnings of viewing depression as an evolutionary adaptation.

Many years later, the “Social Yielding” hypothesis was introduced by John Price and his colleagues. Price argued that depression is the result of an individual that has yet to accept his loss in an unfit situation. Price wrote that in order to alleviate depressive symptoms, individuals have to: (1) end the competition, (2) accept the loss, and (3) outwardly express submission to the winner. If the individual fails to do these three things, chronic depression is the result. While Price’s ideas furthered and expanded ideas regarding evolutionary depression, Price neglected to address the state of the individual after accepting the loss. In order to bring this hypothesis full-circle as a true adaptationist hypothesis, it is necessary to discuss the resulting net benefits that affect the individual’s fitness.

The “Strike” hypothesis was introduced in 1999 by Edward H. Hagen, an anthropologist at the University of California. This hypothesis focused on the adaptive value of depression in partnerships. Hagen argued that depression functions to assist individuals in obtaining greater investments from their partners. This hypothesis can be compared to Lewis’ “cry-for-help” hypothesis, but on an intimate level.

However, Hagen’s hypothesis is narrow, as it is targeted towards the idea of solving intense issues between a pair of individuals. A hypothesis that goes beyond solving relational or commitment issues is necessary when dealing with the large population that depression affects — especially since chronic depression can be seen as early as childhood. The Social Navigation Hypothesis One of the most well-known hypotheses in Darwinian psychology is the Social Navigation Hypothesis (SNH), proposed by Paul J. Watson and Paul W. Andrews. The SNH focuses on how short-term emotional pain can actually provide net benefits for the individual in the future. Watson and Andrews argue that emotional pain should be seen analogously to physical pain. More specifically, Watson and Andrews argue that both physical and emotional pain act as negative feedback mechanisms. For example, physical pain acts as a function to draw attention to environmental problems that threaten the physical well-being of an individual. In the same way, emotional pain acts as a function to draw attention to problems in the social environment that threatens the fitness of the individual.

A similar view was proposed by Davie M. Buss in 1999. However, Buss discussed the role of pleasure as a positive feedback mechanism. Buss argued that actions that enhance an individual’s fitness (i.e., sex, eating, sleep) reward us with feelings of pleasure. These feelings of pleasure further encourage fitness-enhancing behavior.

Watson and Andrews also proposed that emotional pain causes an individual to be more creative and strategic regarding their future decisions. These strategic options would allow the depressed individual to consider costlier and riskier actions than the non-depressed individual would. The wider range of actions that are considered by the depressed individual may lead to net benefits for the depressed in the long-run. Watson and Andrews call this the “social rumination function”. This idea is backed by a study done by Yost and Weary in 1996. In their study, they found that those with depression tend to outperform those without depression on complicated tasks that require complex social problem-solving skills.

Understanding the benefits of emotional pain are key to understanding what Watson and Andrews argue to be the two main social problem-solving functions of the SNH: First, depression induces cognitive changes that focus and enhance capacities for the accurate analysis and solution of key social problems, suggesting a social rumination function. Second, the costs associated with the anhedonia and psychomotor perturbation of depression can persuade reluctant social partners to provide help of make concessions via two possible mechanisms, namely, honest signaling and passive, unintentional fitness extortion. Thus, it may also have a social motivation function.

There is clear evidence to defend the claim that depression serves as a function to solve problems within the social environment. The symptoms of depression ought to resolve themselves once the issues with the social environment are fixed if depression truly does serve as a social problem-solving function. In 1998, T.A. Brown published a study that showed this exactly. Brown found that recovery from depression is accelerated when the individual is surrounded by a strong social support system and works to improve their social relationships.

The DSM IV can also be used as a resource to defend the close ties between social well-being and depression. The DSM IV states that: “…those with major depressive disorder have…greater decreases in physical, social and role functioning”. The decreased social and role functioning reported by the APA both aligns with and supports the SNH. However, despite the copious amounts of evidence that supports the SNH, the SNH would lose its validity if the social beacons of the depressed were left unanswered by others. Watson and Andrews expand on the SNH by explaining why others may feel motivated to help the depressed. This is what they call the “social motivation function”.

The first motivation that Watson and Andrews discuss credits virtue as the motivation to assist the depressed. An individual that is truly struggling with depression is noticeable to others because of how dramatically depression alters their everyday functioning: “… motivating people with a pre-existing interest in helping an individual who honestly signals the need for help…as an honest cry-for-help could motivate social partners to help by virtue of the costs that it imposes on the depressive”. This may account for some of the assistance that the depressed receive, but certainly not all of it. Humans tend to be more egotistic than virtuous in their thoughts and actions, and receiving assistance from others is much more likely if the symptoms of the depressed are bilaterally affecting others around them. The second social motivational function that Watson and Andrews discuss conforms to the idea that humans err more towards egoism than virtue: “Depression also may motivate social partners to provide help via the gradually increasing costs it imposes on them”. In other words, if the costs of depression begin to affect the lives of those around the depressed, others may be more motivated to help the depressed in order to alleviate the costs that the depressed individual is indirectly placing on them.

The third and final social motivational function that Andrew and Watson discuss is what they call the “niche change” function. Like the previous motivational function, the niche change theory is also centered around the idea of egoism. However, the niche change theory accounts for the negative impact that the depressed can burden their social group with: Humans live in groups where diverse goods and services are exchanged according to complex, heavily negotiated social contracts. An individual’s “social niche” is defined by the interacting reciprocal exchange contracts they hold with each person in their social network, coupled with the skills and strategies they use to create, maintain, and modify these contracts. Watson and Andrews argue that if an individual is placed in a niche that is unfit for them, they will experience symptoms of depression until they can be placed in a niche that is fitting for them. However, niche change often requires the assistance of others, whether it is: “…in the form of political favors, skill training, capital investment, or savvy brainstorming about better niches”.

The Gender Differential Hypothesis

As we have seen, the social environment of an individual is closely associated with the signs and symptoms of depression. Therefore, I think that the SNH is the most promising adaptationist hypothesis. However, I do have a few critiques and ideas to add to the hypothesis. One of the biggest concerns that the SNH raises is its failure to expand on different social situations and problems (i.e., gender, race, culture) that cause individuals to exhibit symptoms of depression. Simply calling situations “unfit” is too vague, and further explanation is needed. Specifically, the SNH does not address the prevalence of depression between genders, despite the fact that women are twice as likely to develop depression in their lifetime than men. It seems absurd to neglect such a staggering statistic in such a thoughtful and comprehensive theory. It is because of this weakness found in the SNH that I developed the Gender Differential Hypothesis (GDH). The GDH should not be thought of as a separate adaptationist theory, rather, it should be considered an expansion to the SNH. The GDH argues that the reason women are twice as likely as men to be diagnosed with depression is because of the social oppression that females have dealt with. Females have faced radical social oppression historically, and they still do to this day.

Currently, women are faced with lower wages, workplace bias, and sexual harassment. Prior to these struggles, women were faced with exhausting familial and domestic expectations, lack of education and income opportunities, and lack of political rights. There is a greater chance that the oppressed will need extra social help due to the difficulties that they face physically and emotionally. If for one reason or another social help is not provided, the oppressed individual will continue to increasingly develop symptoms of depression until social help is available. The GDH can be defended by utilizing prior surveys and studies. For example, the APA reported that gender does not play a role in prepubescent depression rates, but by age 15, females become twice as likely as males to develop depression. The GDH attributes the sudden increase in female depression to the maturation of the female. During puberty, the female begins to recognize and understand her social oppression. This oppression will cause symptoms of depression in females that require extra social help, and the depression will continue until adequate social assistance is received. While there is no formal method developed for testing the GDH, we can test its accuracy by assuming that the rates of depression in other oppressed groups would be higher than those of other non-oppressed groups. If this proves to be the true, then one could claim that the GDH has merit. To test this, we can utilize a study was done at the University of Queensland in 2013 regarding rates of depression around the world. As the GDH would predict, the highest rates of depression were recorded in some of the most oppressed places — like Tanzania and Afghanistan. Other fairly unoppressed places — such as the United States and Europe — had lower rates of depression.

Treatment of Depression

The SNH suggests that depression should be treated with SNH-based informed therapy. In this therapy, the therapist would educate the patient on the SNH while also assisting them in navigating through their social problems until a solution is reached. The navigation of social issues would most likely include group and family therapy. The SNH believes that SNH-based informed therapy is all that is needed to treat depression because anti-depressants may affect the patient’s ability to dissect and make changes to their social environment. SNH-based informed therapy accompanies the SNH nicely, however; I believe that there are other statistically significant forms of psychotherapy that are worth considering. The most common psychotherapy used to treat depression today is cognitive behavioral therapy, or CBT.

Cognitive behavioral therapy is a psychosocial form of therapy that focuses on how an individual’s thoughts, attitudes, and beliefs can affect their feelings and behavior. CBT focuses on teaching the patient coping mechanisms for various problems that the patient and therapist feel need to be addressed. I believe that CBT should be the therapy of choice for treating those with depression because the efficacy is proven. A 2012 study conducted by Stefan G. Hoffman showed that compared to other therapies, CBT was the most effective therapy for treating individuals with depression.

I disagree with the SNH regarding the use of anti-depressants to treat depression. I believe that anti-depressants should be offered and encouraged to patients coping with depression. Once again, there are studies that outline the efficacy of anti-depressants that should not be ignored. Up to 60% of people that took an anti-depressant reported an improvement in their symptoms from the medication. Those with chronic or severe depression would find it beneficial to try anti-depressants as another resource for controlling unwanted feelings of depression.

Overall, I believe that a combination of cognitive behavioral therapy and anti-depressant medication is the most effective way to treat depression. Anti-depressants work to help regulate brain chemistry, while CBT works to evaluate the life of the depressed, make necessary adjustments, and reevaluate after changes in thinking and coping are applied.

Conclusion

Darwinian psychology is still one of the minority views that tries to understand and explain the function of depression. There are many scientists and psychologists that strongly believe that depression is simply a maladaptation with no fitness-enhancing functions. However, adaptationist views of depression offer promising ideas regarding depression that should not be ignored; especially since the biological bases of depression are still relatively mysterious to scientists.

Finally, the social navigation hypothesis and the gender differential hypothesis work together to explain why there is a “gender gap” in depression — a feat that still lacks adequate discussion by scientists and adaptationists alike. As Albert Einstein once said: “The true sign of intelligence is not knowledge, but imagination.” We must, as scientists and philosophers, step out of our comfort zone and allow our creativity to help us form hypotheses we never thought imaginable. It is these profound and exotic hypotheses that end up answering unsolved questions and changing the course of science.

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