Evolutionary Psychology Flashcards
What is evolution ?
- Descent with modification
- Descent = a lineage of organisms characterised by hereditary similarity between parents and offspring
- Modification = changes across generations in the distribution of characteristics, or traits, in a lineage
- So evolution = the change in the frequencies of hereditary characteristics across generations in a lineage
What causes evolution?
- Natural selection
- Pre-requisite: Within a species there is heritable variability of phenotypes (caused by mutations or recombination during sexual reproduction)
- Some variations result in more offspring (differential reproductive success); these offspring will themselves therefore possess these beneficial differences, i.e., natural selection
Different types of evolutionary fitness?
- Classical fitness = a measure of an individual’s ability for direct reproductive success
- Inclusive fitness = a measure of an individual’s ability for both direct and indirect reproductive success (Hamilton 1964)
What are the products of evolution?
- Adaptations: Inherited characteristics that emerged through natural selection because they aided in solving problems related to survival and/or reproduction. - Example: umbilical cord
- By-products: Characteristics that do not solve adaptive problems and do not have functional design. They are coupled to adaptations. - Example: belly button
- Noise: Random effects produced by chance mutations that do not affect survival and/or reproductive success.
EP: Confirmation of Darwin’s prediction?
- “In the distant future … psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation.” (On the Origin of Species, 1859)
- Evolutionary Psychology: “The mind is a set of information-processing machines [modules] that were designed by natural selection to solve adaptive problems faced by our hunter-gatherer ancestors” (Cosmides & Tooby, 1997, p. 1)
Evolutionary Psychology vs. evolutionary psychology?
- Evolutionary Psychology: - “A way of thinking about psychology that can be applied to any topic within it” (Cosmides & Tooby, 1997, p. 1)
- “Most important scientific revolution in the history of psychology” (David Buss)
- V.S. evolutionary psychology: (Merely another) field of inquiry; a sub-discipline/approach within psychology.
The goal of Evolutionary Biology + Cognitive Psychology
- Goal is to understand the human mind/brain from an evolutionary perspective
- The mind is composed of many innate, specialised, modules ‘designed’ by natural selection
- These modules emerged through natural selection to solve pre-historical adaptive problems (1.8 million – 10,000 years ago).
What is EP reacting against?
- Standard Social Science Model (SSSM):
1. Non-human animals are rigidly controlled by their biology, human behaviour determined by culture.
2. Human infants born with nothing apart from a few reflexes and an ability to learn.
3. Learning is a general-purpose process used in all domains of knowledge; children learn how to behave in their culture through imitation, reward, and punishment.
Core Tenets of EP
- All behaviour is a function of psychological mechanisms + input to those mechanisms
- Not generally controversial but according to proponents of EP it needs emphasising:
- “it is clear that no behavior can be produced in the absence of psychological mechanisms” (Buss, 1995)
“Modern skulls house a stone-age mind” (Cosmides & Tooby, 1997)
- Natural selection designed our minds to deal with problems that our ancient ancestors faced on the African savannahs
- This was our Environment of Evolutionary Adaptedness (EEA; 1.8 million – 10,000 years ago) and still is.
Characteristics of the EEA
- The EEA probably consisted of:
- Hunter/gatherer/scavenging subsistence
- Nomadic or semi-nomadic
- Low population density
- Small kin-based groupings
- Simple technology
- High infant mortality and low life expectancy
- Vulnerability (e.g., to predators, disease)
- Few lifestyle options
- Development of agriculture, living in towns, cities: Only 10,000 years ago (~1000th of human history!)
Adaptive Problems in the EEA
- Our minds were designed by natural and sexual selection to solve adaptive problems faced by our hunter-gatherer ancestors:
- Surviving/avoiding predators
- Food selection
- Attracting mates
- Forming reciprocal alliances
- Parenting
- Reading others people’s minds
- All of these play a role in the success with which one’s genes are passed on. So natural selection designed mental mechanisms to solve these problems (Evolved Psychological Mechanisms)
The Massive Modularity Hypothesis
-Our mind consists of many domain-specific information processing modules (Evolved Psychological Mechanisms)
-Each is “an expert in one arena of interaction with the world” (Pinker, 1997)
E.G.,
-Mate selection; Theory of mind; Perception of colour; Language; Detecting cheaters during social exchanges
Mismatches between EEA and current environment
- Modern fear responses reflect ancient dangers (Ohman & Mineka, 2001)
- “Supernormal stimuli” (Barrett, 2010)
Ultimate and Proximate Causation
- Evolution produces adaptations that on average increase survival/reproductive fitness.
- We do not (necessarily) do those things that maximize fitness today; we execute those adaptations that in the past increased fitness.
- WHY does a certain trait exist?
- ULTIMATE CAUSE – the reason why it increased fitness in the evolutionary past
- PROXIMATE CAUSE – the immediate psychological, physiological, biochemical, and environmental reasons