EVOLUTIONARY PSYCHOLOGY NOTES
1. Basics of Evolutionary Biology
What is Evolutionary Biology?
Evolutionary biology is the study of how life changes over time through mechanisms like natural
selection, genetic drift, mutation, and gene flow. It explains how species adapt to their
environments and how new species emerge.
Key Concepts:
Natural Selection: Proposed by Charles Darwin, it states that organisms with traits that help
them survive and reproduce are more likely to pass those traits to the next generation.
Mutation: Random changes in DNA that can create new traits.
Genetic Drift: Random changes in gene frequencies in a population, often seen in small
populations.
Adaptation: Traits that improve survival or reproduction in a given environment.
Speciation: The formation of new species through evolution.
Example:
The peppered moth changed from light-colored to dark-colored during the Industrial
Revolution due to pollution, showing adaptation through natural selection.
2. Gene-Culture Co-evolution
What is Gene-Culture Co-evolution?
Gene-culture co-evolution is the idea that human genetic evolution and cultural evolution interact
and influence each other. This means that human behavior is shaped by both genetic traits and
cultural practices.
How Does It Work?
Culture influences genetic selection: When a cultural practice becomes widespread, it can
create new selective pressures on genes.
Genes influence culture: Certain genetic traits make some cultural practices more successful.
Examples:
1. Lactose Tolerance: In regions where dairy farming became common, people with genes for
lactose digestion had a survival advantage, leading to the spread of lactose tolerance.
2. Sickle Cell Trait and Malaria Resistance: In areas with high malaria risk, populations
developed genetic resistance to malaria, which also influenced local cultural practices around
medicine and disease prevention.
, 3. Individual Similarity and Difference
What Determines Individual Differences?
Humans are similar in many ways, but they also have unique differences due to a combination of
genetics and environment.
Factors Influencing Individual Differences:
1. Genetics
o Inherited traits from parents (e.g., eye color, height, intelligence potential).
2. Environment
o Cultural background, education, nutrition, and life experiences.
3. Gene-Environment Interaction
o Some traits develop based on genetic predisposition but require an environmental
trigger (e.g., musical ability may require training).
Example of Individual Differences:
Twin Studies: Identical twins (same DNA) raised in different environments still show
similarities but also develop unique traits due to their environment.
4. Origin of Morality / Ethical Consistency
How Did Morality Evolve?
Morality evolved as a social survival strategy. Humans who cooperated and followed ethical norms
had better survival and reproductive success.
Key Theories:
Evolutionary Ethics: Suggests that morality developed because cooperation helped humans
survive in groups.
Reciprocal Altruism: Helping others increases the likelihood of receiving help in return.
Kin Selection: We are more likely to help relatives because they share our genes.
What is Ethical Consistency?
Ethical consistency means applying moral principles uniformly across different situations.
It prevents hypocrisy and moral contradictions.
Example:
If a person believes stealing is wrong, they should consider it wrong in all cases—not only
when it affects them personally.
5. Empathy, Excellence, and True Professionalism
1. Basics of Evolutionary Biology
What is Evolutionary Biology?
Evolutionary biology is the study of how life changes over time through mechanisms like natural
selection, genetic drift, mutation, and gene flow. It explains how species adapt to their
environments and how new species emerge.
Key Concepts:
Natural Selection: Proposed by Charles Darwin, it states that organisms with traits that help
them survive and reproduce are more likely to pass those traits to the next generation.
Mutation: Random changes in DNA that can create new traits.
Genetic Drift: Random changes in gene frequencies in a population, often seen in small
populations.
Adaptation: Traits that improve survival or reproduction in a given environment.
Speciation: The formation of new species through evolution.
Example:
The peppered moth changed from light-colored to dark-colored during the Industrial
Revolution due to pollution, showing adaptation through natural selection.
2. Gene-Culture Co-evolution
What is Gene-Culture Co-evolution?
Gene-culture co-evolution is the idea that human genetic evolution and cultural evolution interact
and influence each other. This means that human behavior is shaped by both genetic traits and
cultural practices.
How Does It Work?
Culture influences genetic selection: When a cultural practice becomes widespread, it can
create new selective pressures on genes.
Genes influence culture: Certain genetic traits make some cultural practices more successful.
Examples:
1. Lactose Tolerance: In regions where dairy farming became common, people with genes for
lactose digestion had a survival advantage, leading to the spread of lactose tolerance.
2. Sickle Cell Trait and Malaria Resistance: In areas with high malaria risk, populations
developed genetic resistance to malaria, which also influenced local cultural practices around
medicine and disease prevention.
, 3. Individual Similarity and Difference
What Determines Individual Differences?
Humans are similar in many ways, but they also have unique differences due to a combination of
genetics and environment.
Factors Influencing Individual Differences:
1. Genetics
o Inherited traits from parents (e.g., eye color, height, intelligence potential).
2. Environment
o Cultural background, education, nutrition, and life experiences.
3. Gene-Environment Interaction
o Some traits develop based on genetic predisposition but require an environmental
trigger (e.g., musical ability may require training).
Example of Individual Differences:
Twin Studies: Identical twins (same DNA) raised in different environments still show
similarities but also develop unique traits due to their environment.
4. Origin of Morality / Ethical Consistency
How Did Morality Evolve?
Morality evolved as a social survival strategy. Humans who cooperated and followed ethical norms
had better survival and reproductive success.
Key Theories:
Evolutionary Ethics: Suggests that morality developed because cooperation helped humans
survive in groups.
Reciprocal Altruism: Helping others increases the likelihood of receiving help in return.
Kin Selection: We are more likely to help relatives because they share our genes.
What is Ethical Consistency?
Ethical consistency means applying moral principles uniformly across different situations.
It prevents hypocrisy and moral contradictions.
Example:
If a person believes stealing is wrong, they should consider it wrong in all cases—not only
when it affects them personally.
5. Empathy, Excellence, and True Professionalism
