The Evolutionary Mechanism of Human Dysfunctional Behavior: Relaxation of Natural Selection Pressures throughout Human Evolution, Excessive Diversification of the Inherited Predispositions Underlying Behavior, and Their Relevance to Mental Disorders

Why is humanity by far the most successful animal in the animal kingdom, but when it comes to survival of the fittest, we pull against the impulse toward natural selection? Unique among vertebrates, humans develop and practice varied forms of dysfunctional or maladaptive behavior, the graver of which are categorized as mental disorders, which doesn''t sustain our species. Dr. Ivan Fuchs explains why this is the case, setting his discussion within the fields of psychiatry, evolutionary biology, and genetics, marshalling a wide-range research to make a compelling case.

In this work, Dr. Ivan Fuchs provides his theory on human dysfunctional behavior rooted in Darwinian evolutionary thinking. His theory includes:

1. An attempt to identify the basic evolutionary mechanism that leads to dysfunctional or maladaptive behavior that is increasing in human populations. He proposes that this mechanism consists of progressive relaxation of selection pressures originating in the natural environment as a result of the technological and cultural development in human civilization. These developments protect against many natural inconveniences and dangers such as harmful weather conditions; scarce or unreliable food supplies; cruel, even deadly competition for life-sustaining or reproductive resources; danger of predation, and so on. The relaxation of natural selection pressures leads to excessive diversification of innate predispositions that, due to the complexities of social coexistence, has both far-reaching beneficial, as well as harmful, consequences.

2. Dr. Fuchs deals primarily with severe forms of dysfunctional behavior (categorized as mental disorders), pinpointing those genetically based behavioral complexes which predispose humans to anxiety, affective and personality disorders, paranoia, and schizophrenia.

3. Dr. Fuchs also makes clear that the above innate predispositions cannot lead by themselves to the whole clinical picture of diagnosable mental disorder categories. In order for full-blown clinical symptomatology to develop, the innate predisposition has to interact with influences after childbirth, first of all, learning. Consequently, psychiatric understanding and research has to distinguish sharply between those mental (brain) structures and functions which constitute the innate predisposition to a certain mental disorder versus those ones involved secondarily during the lifespan. This consideration is detailed in the case of schizophrenia spectrum of disorders.

The above theoretical considerations have important therapeutic, preventive and research implications. See more