1: Evolution and Development of Mental Disorders Flashcards
What is the paradox of mental disorders?
- Mental disorders are common
- High heritability
- People with mental disorders get less children
Why did natural selection not eliminate mental disorders from the population?
Why do people with mental disorders get less children?
Mental disorders cause lower fertility in both men and women which causes lower reproductive succes.
In short, what are the 3 general resolutions of the paradox?
- Ancestral neutrality
- Balancing selection
- Polygenic mutation-selection balance
Explain ancestral neutrality.
Mental disorders tend to have a negative impact on reproductive succes nowadays in modern countries, but the fitness effects were neutral in ancestral times
What is the criticism on ancestral neutrality?
The prevalence is still high, where you would expect it to go down.
Explain balancing selection.
Mental disorders tend to have a negative impact on reproductive succes, but this is counterbalanced by positive effects.
What is the criticism on balancing selection?
There is no balance, because in fact the reproductive succes is lower.
What is the criticism on balancing selection?
There is no balance, because in fact the reproductive succes is lower.
- Also brothers and sisters of mental disordered dont get more kids
Explain polygenic mutation-selection balance.
Mental disorders are the result of unavoidable mutations in one or more of the thousands of genes that underlie human behavior
What is the criticism on polygenic mutation-selection balance?
Heritability is high
What is proof for the polygenic mutation-selection balance?
- No succes in ‘gene hunting’, so must be polygenic
- High comorbidity among disorders
- Association between inbreeding and disorders
- Association between paternal age and disorders > if man older, more mutations in sperm.
