Evolutionary Psychology
Evolutionary psychology (EP) is the study of human psychological traits as evolutionary adaptations — mechanisms shaped by natural and sexual selection over millions of years, primarily during the Pleistocene epoch (~2.6 million to 11,700 years ago), when most of human evolution occurred.
Primary source introducing this domain to the wiki: miller-2001-mating-mind
Core Premises
- The mind is not a blank slate — it contains evolved psychological mechanisms (EPMs) that constitute human nature. These are not cultural inventions but biological inheritances.
- Adaptation is the unit of analysis — each psychological mechanism should be analysed in terms of the adaptive problem it solved and the environment in which it evolved (the Environment of Evolutionary Adaptedness, or EEA).
- The EEA is primarily the Pleistocene — our ancestors lived as hunter-gatherers in small bands for ~99% of human evolutionary history. Modern environments differ radically; many mismatches between evolved psychology and modern contexts produce maladaptive behaviour.
- Both natural and sexual selection shaped the mind — survival pressures shaped cognitive tools (planning, tool use, language for coordination); mating pressures (see sexual-selection) shaped display capacities (art, music, humour, language creativity).
Key Domains
Mating Psychology
sexual-selection shaped extensive psychological mechanisms related to mate choice, mate retention, jealousy, and intrasexual competition. Miller’s miller-2001-mating-mind argues that this is under-estimated as a force in shaping cognition and creativity.
Mate preferences show consistent cross-cultural patterns:
- Females prioritise resource access, status, intelligence, and reliability
- Males prioritise youth, physical health indicators (symmetry, waist-hip ratio), and fertility signals
Social Cognition
Hominids lived in groups of ~50–150 (Dunbar’s number). This produced adaptations for:
- Theory of mind — modelling other agents’ beliefs and intentions
- Coalition detection — tracking alliances and betrayals
- Cheater detection — identifying those who take without contributing (Wason selection task)
- Status tracking — reading and navigating social hierarchies (connects to social-skills)
Cognitive Heuristics
The heuristics documented by daniel-kahneman and amos-tversky (see heuristics, cognitive-biases) are evolutionary adaptations that worked well in ancestral environments but misfire in modern statistical and financial contexts. The availability heuristic, for example, was adaptive when recent memories reliably tracked real-world frequencies; it misfires when media creates a vivid but unrepresentative sample.
Emotions as Evolved Programs
Emotions are not irrational noise but information-processing programs evolved to solve adaptive problems: fear activates threat response, disgust avoids pathogens, jealousy guards mating relationships, social pain motivates reintegration after exclusion.
Miller’s Contribution: Sexual Selection and the Mind
geoffrey-miller extended EP by arguing that mate choice — not just survival — was the primary driver of the human mind’s most distinctive and elaborate features:
| Human capacity | Standard EP account | Miller’s account |
|---|---|---|
| General intelligence | Survival tool (planning, coordination) | Fitness indicator signalling genetic quality |
| Language | Communication and coordination | Verbal courtship display |
| Art and music | Cultural byproduct or social bonding | Costly fitness indicator (ornamental waste) |
| Humour | Social bonding | Display of cognitive agility to potential mates |
| Moral virtue | Cooperation / reciprocal altruism | Fitness display: costly altruism signals gene quality |
This is a substantial theoretical extension of EP: if Miller is right, human culture is partly the archaeological record of mate choice.
The Pleistocene as the Reference Environment
EP analyses behaviour relative to the Pleistocene EEA, but acknowledges several complications:
- Humans evolved across diverse African environments, not a single EEA
- Cultural evolution has dramatically altered selection pressures, especially in the Holocene
- Many modern environments (cities, financial markets, social media) have no Pleistocene equivalent
This produces evolutionary mismatches: mechanisms evolved for one environment misfire in another. Sugar craving (adaptive when fruit was scarce) causes obesity in a world of abundant refined sugar. Fear of strangers (adaptive in small band societies) produces racism in multicultural cities.
Relationship to Other Concepts
- sexual-selection — the key theoretical engine Miller uses to explain human mental evolution
- fitness-indicators — the honest-signal mechanism connecting costly traits to genetic quality
- cognitive-biases — biases as evolutionary mismatches between ancestral and modern environments
- social-skills — social behaviour as partly rooted in evolved display and coalition mechanisms