Evolutionary Foundations for Psychiatric Research and Practice

Vocabulary flashcards summarizing key evolutionary biology and psychiatry concepts, mechanisms, theories, and clinical applications discussed in the lecture notes.

Evolutionary Psychiatry

A field that integrates evolutionary theory with psychiatric research and practice to explain why the mind and its disorders are the way they are.

Proximate Explanation

Describes HOW a trait works (mechanism & development) within an individual.

Evolutionary (Ultimate) Explanation

Describes WHY a trait exists by examining its adaptive value and phylogenetic history.

Tinbergen’s Four Questions

A framework requiring answers about mechanism, ontogeny, phylogeny, and adaptive significance to fully explain any trait.

Mechanism (Tinbergen)

How a trait functions at molecular, physiological, and behavioral levels.

Ontogeny (Tinbergen)

How a trait develops from zygote to adult within an individual.

Phylogeny (Tinbergen)

The evolutionary history of a trait across species.

Adaptive Significance (Tinbergen)

The fitness advantages that shaped a trait through natural selection.

Behavior Regulation Mechanism

Neural systems shaped by selection that flexibly adjust behavior to maximize fitness.

Inclusive Fitness

An individual’s own reproductive success plus effects on the reproduction of genetic relatives.

Kin Selection

Selection favoring behaviors that help genetic relatives, summarized by Hamilton’s rule (C < B × r).

Hamilton’s Rule

A costly act spreads if cost (C) is less than benefit to the recipient (B) times relatedness (r).

Selfish Gene Concept

The idea that genes promoting their own replication shape organismal traits, sometimes leading to generosity for inclusive fitness gains.

Evolutionary Medicine

Applies evolutionary principles to understand why bodies are vulnerable to disease.

Mismatch Hypothesis

Diseases arise when modern environments differ from ancestral ones for which traits were adapted.

Evolutionary Constraints

Limitations preventing selection from producing perfect designs (e.g., blind spot, narrow birth canal).

Host-Pathogen Arms Race

Continuous co-evolution of defenses and counter-defenses between hosts and rapidly evolving pathogens.

Trade-Off

Improvement in one aspect of a trait that causes detriment in another aspect (e.g., anxiety vs. opportunity).

Reproduction-Health Conflict

Alleles increasing reproduction can spread even if they harm health or longevity.

Defense vs. Disease

Pain, fever, cough, panic, etc., are protective responses, not diseases themselves.

Smoke Detector Principle

Defensive systems are biased toward false alarms because misses are far costlier than unnecessary responses.

Natural Selection

Differential reproductive success of heritable variants producing adaptation (mnemonic VISTA).

VISTA

Variation, Inheritance, Selection, Time → Adaptation.

Mutation

Random genetic change providing raw material for evolution; important in psychiatric disorders like schizophrenia.

Genetic Drift

Random fluctuation of allele frequencies, especially in small populations.

Migration (Gene Flow)

Movement of alleles between populations, altering trait prevalence (e.g., lactase persistence).

Plasticity (Facultative Adaptation)

Ability of mechanisms to adjust phenotype to current environments (e.g., tanning, shivering).

Sexual Selection

Subtype of natural selection driven by competition for mates and mate choice (e.g., peacock tails).

Social Selection

Selection resulting from competition for social resources like status, alliances, and group membership.

Male–Female Mortality Gap

Higher early adult male mortality due to risk-taking traits favored by sexual selection.

Concealed Ovulation

Hidden fertility in humans, possibly promoting pair bonds and paternity certainty.

Fast-Life Strategy

Life-history pattern favoring early reproduction, risk-taking, and low parental investment in harsh, unpredictable environments.

Slow-Life Strategy

Life-history pattern favoring delayed reproduction, high parental investment, and risk aversion in stable environments.

Behavioral Ecology

Studies how behavior optimizes fitness trade-offs in specific ecological contexts.

Somatic Effort

Energy spent on growth, maintenance, and personal survival.

Reproductive Effort

Energy invested in mating and parenting.

Social Effort

Energy allocated to forming alliances, gaining status, and maintaining relationships.

Review of S.O.C.I.A.L. Systems

Clinical tool assessing Social status, Occupation, Children/family, Income, Abilities/appearance/health, and Love/sex.

Charnov’s Marginal Value Theorem

Model predicting when to leave a declining resource patch based on average returns elsewhere.

Reciprocal Altruism

Helping non-kin with expectation of future return; evolutionary basis for friendship and guilt.

Prisoner’s Dilemma

Game-theory model illustrating tension between cooperation and defection.

Tit-for-Tat Strategy

Reciprocate other’s previous action; fosters alternating cooperation/defection cycles.

Involuntary Yielding Hypothesis

Depression as adaptive submission after status defeat to prevent further attack.

Cliff-Edge Fitness Model

Trait pushed close to failure point (e.g., cognition in schizophrenia) to gain advantages until rare breakdowns occur.

Gene-Culture Coevolution

Mutual feedback where cultural practices alter selection pressures, shaping genetic evolution (e.g., dairying & lactase).

Personality as Social Strategy

Personality traits reflect evolved tactics for resource acquisition; disorders are extreme, rigid versions.

Sociopathy (Antisocial Traits)

Low empathy, deceitful strategy that may persist via frequency-dependent selection when cooperators are common.

Obsessive-Compulsive Personality

Extreme conscientious strategy expecting reciprocity; leads to disappointment and rigidity.

Borderline Pattern

Rapidly intense commitment followed by withdrawal when reciprocity fails; reflects maladaptive relationship strategy.

Anxiety

Defense aroused by potential threats; useful but prone to false alarms (e.g., social anxiety).

Hypophobia

Deficiency of fear response, leading to risk-taking and danger.

Low Mood (Sadness/Depression)

State reducing motivation when goals seem unreachable; can conserve energy and promote reevaluation.

Mania

Excessive positive mood, risk-taking, and energy; costly despite short-term gains.

Jealousy

Emotion triggered by threat to mate or fidelity; evolved to protect reproductive interests.

Social Anxiety

Fear of negative social evaluation; adaptive due to high stakes of group acceptance.

Smoke Detector Analogy for Panic

Panic attacks represent false alarms from a defense system calibrated to avoid lethal misses.

Mismatch & Substance Abuse

Addictive drugs exploit neural reward systems that evolved without exposure to purified substances.

Dieting-Binge Cycle

Strict calorie restriction triggers ancestral famine responses, promoting bingeing and weight gain.

Step-Parent Effect

Higher rates of child abuse in households with unrelated adult, consistent with inclusive-fitness predictions.

Imprinting (Genomic)

Parent-of-origin gene silencing causing conflicts (e.g., IGF-II & IGF-IIr, linked to autism/schizophrenia hypotheses).

Weaning Conflict

Mother–infant tug-of-war over nursing duration due to differing genetic interests.

Pathogen-Trigger for OCD

Streptococcal mimicry can provoke autoimmune reactions causing OCD or Sydenham’s chorea.

Myopia as Genetic Quirk

Highly heritable nearsightedness manifests mainly in modern reading environments—example of gene-environment interaction.

Epistasis

Interaction between different genes affecting trait expression and fitness.

Plastic Emotional System

Emotion regulation shaped by selection to adjust responses based on context and learning.

Mutualism

Cooperation benefiting all parties without risk of defection (e.g., moving a heavy rock together).

Spite

Costly action aimed to harm a defector; deters future exploitation.

Altruistic Punishment

Willingness to punish cheaters even at personal cost, supporting group cooperation.

Phylogenetic Continuity of Emotions

Emotions evolved from earlier forms, forming overlapping clusters rather than discrete categories.

Basic vs. Dimensional Emotions

Evolutionary view accepts partial overlaps—emotions are neither entirely discrete nor purely dimensional.

Adaptive Value of Negative Emotion

Painful feelings exist because they historically increased ancestors’ fitness.

False Alarm (Emotion)

Useless anxiety or depression arising from normal defense bias toward safety.

Frequency-Dependent Selection

Fitness payoff of a strategy depends on how common it is in the population.

Null Model in Population Genetics

Assumes allele frequency changes by drift alone; baseline for testing selection hypotheses.

Stone-Age Minds Myth

Humans have continued evolving; not frozen in Pleistocene adaptations.

Post-Menopausal Selection

Grandmothering can enhance inclusive fitness, so selection still acts after reproductive years.

Evolutionary Null vs. Abnormality

Absence of adaptive explanation doesn’t imply disorder; some traits are neutral quirks.

Evolutionary Framework for DSM

Suggests integrating context and defense function into diagnostic criteria beyond frequency/severity.