Study Notes on Evolutionary Perspective of Emotion
Evolutionary Perspective on Emotion
What Is an Evolutionary Perspective?
Charles Darwin (1809–1882) is one of the most influential figures in modern biology.
He not only explained how species evolve but also suggested that human emotions have evolutionary roots.
Emotional Expressions Across Species
Darwin noticed emotional expressions across species.
He observed that humans and animals show similar emotional expressions.
Some emotions are universal → not only cultural, but biological.
Evolutionary Roots of Emotions
He proposed that emotional expressions are part of our evolutionary heritage.
WE WERE born with them, not learned.
Emotions and Human Survival
How did emotions help humans survive long ago?
Fear helped early humans run from lions.
Love helped parents take care of babies.
Emotions are not random; they are tools for survival.
The question arises: Why do emotions exist?
Darwin’s Ideas on Emotion
Emotional expressions are natural.
Fear, anger, joy appear in humans and animals.
Adaptive Roles of Emotions
Fear: Helps escape predators.
Anger: Mobilizes energy for defense.
Love and attachment: Strengthen caregiving and group cohesion.
Functional Nature of Emotions
The evolutionary perspective suggests that emotions are functional.
They help survival and reproduction.
Examples of functional emotions:
Fear: Runs away from predator → stays alive.
Love: Parents care for children → children survive.
Disgust: Avoids rotten food → avoids disease.
Survivorship and Emotional Genes
Important: People who had strong emotions survived and passed genes to their children.
People without emotions did not survive as well.
Genetics and Evolution
Genes and DNA
Genes are DNA instructions passed from parents to children.
Genes are tiny parts inside our cells and are like recipes for building the body.
Evolutionary stories begin with genes.
Genes are made of DNA and tell the body how to grow and work.
A gene decides eye color.
Another gene decides blood type.
Without genes, no evolution is possible.
Chromosomes and Alleles
Genes are found on chromosomes, which come in pairs.
Alleles are different versions of the same gene (e.g., eye color).
Chromosomes are long strands of DNA, with specific genes having multiple versions called alleles.
Darwin and Gene Understanding
Darwin developed his theory of evolution but did not know about genes.
He understood that traits were passed down, but not how.
This knowledge was added by modern science later.
The Modern Evolutionary Theory
Modern evolutionary theory combines Darwin’s idea of natural selection with Gregor Mendel’s work on inheritance.
The role of DNA became clear in the 1950s.
Today's Evolutionary Theory
Today’s evolutionary theory = Darwin + Mendel + DNA.
Understanding Mutations
Gene Replication and Mutations
Replication: Genes make copies of themselves.
Sometimes gene copying goes wrong by chance, resulting in mutations.
Some mutations are detrimental while others can be advantageous.
Types of Mutations
Harmful mutations: Increase risk of disease.
Neutral mutations: Have no effect on survival.
Helpful mutations: Improve adaptation (e.g., resistance to malaria).
Helpful mutations spread through populations via natural selection.
Natural Selection Basics
Natural selection = “survival of the fittest.”
Bad genes disappear, and good genes proliferate.
In natural selection, problematic genes are removed, while beneficial genes spread through the population.
Beneficial characteristics that spread are referred to as adaptations.
Example of Natural Selection
Giraffes with longer necks could reach food, allowing them to survive better.
Over time, the entire species may change.
Adaptation Process
Traits that harm survival tend to disappear, while traits that facilitate survival and reproduction spread.
Over generations, these advantageous traits are termed adaptations.
Understanding Adaptations
Adaptations are traits that have been preserved because they helped survival.
Examples include fear responses such as rapid heartbeat, sweating, and alertness that help detect and escape danger.
Color vision helps distinguish ripe fruits from unripe or dangerous ones.
Social bonding and attachment ensure infants remain close to caregivers, enhancing their chances of survival.
Functional Traits in Evolution
In evolution, “functional” carries a unique meaning: it describes traits that help survival or reproduction.
It does not equate to being “good,” “moral,” or “nice.”
For example, a fear of snakes is functional due to its role in survival, even if the emotion itself feels unpleasant.
Functional Traits Criteria
Rule 1: A trait is functional if it contributes to a lifespan long enough to reproduce.
Rule 2: Functional traits also assist in having more offspring than others (e.g., people who enjoyed sweet foods consumed more calories and had more energy, living longer and having more children).
Rule 3: Kin selection - A trait is functional if it aids family survival and reproduction (e.g., helping one’s siblings’ children spreads shared genes).
Important Takeaways on Functionality
Important: Functional does not equate to moral judgment.
Adaptive traits may have been beneficial in the ancestral environment but may present challenges today.
Example of Adaptive Traits
A gene might make a person want to eat excessively, which was once essential for survival but can lead to obesity in modern contexts.
Fear of snakes helped in the jungle but remains despite the absence of snakes in cities today.
Environment of Evolutionary Adaptedness (EEA)
Traits evolved in specific environments long ago, known as the Environment of Evolutionary Adaptedness (EEA).
While these traits proved useful historically, they may not fit modern life.
Cravings for sugar were beneficial when food was scarce but can lead to obesity today.
Modern Mismatch
Lesson: Evolution has instilled emotions and desires that sometimes do not align with contemporary life.
Emotions as Adaptations
When researchers assert that emotions evolved, they mean:
Genes endow us with the capacity for emotion.
These genes originated as random mutations.
Process of Emotional Evolution
Steps in How Emotions Spread
People had small random gene changes.
Some changes resulted in emotions.
Those with emotions survived and had children.
Consequently, emotions spread throughout the population.
Today, all humans have emotions as a result of this progression.
Universality of Emotions
If emotions are indeed adaptive, they ought to manifest across all cultures and species.
These emotional responses form a part of human nature.
Other animals also share emotional systems; for example, smiling when happy is universal, and fear in both animals and humans works to avoid predators.
Cultural Expression of Emotions
Culture might influence the way emotions are expressed, but their existence is universal.
Emotional Expressions in Animals
Evolution tends to maintain old traits.
If an ancestor exhibited an emotion, it is likely that both humans and animals share it.
Example: Monkeys, dogs, and humans show fear and happiness.
Example: Rats exhibit laughter when tickled.
Adaptations and Contextual Utility
Utility of Fear
Fear plays a critical role in escaping danger, which is beneficial across numerous species.
For instance, a rabbit flees from a fox; a deer avoids a lion.
Investigating animals can offer insights into human fear responses as well.
Drawbacks of Adaptations
Not all adaptations serve every scenario; for example, anger can lead to irrational actions.
In modernity, anger may result in fights, accidents, or legal trouble.
Anger in Historical Context
Anger played a distinct function in the past:
It enabled individuals to reclaim stolen resources, defend family, or preserve respect.
Displaying anger served as a warning to prevent deceit.
In small communities, these displays could bolster survival.
The Modern Context of Anger
However, anger in the modern world can have severe consequences.
Examples include road rage leading to accidents and violent outbursts resulting in imprisonment.
Universal but Divergent Adaptations
Adaptations are ubiquitous but manifest differently across cultures.
Basic emotions may be universal, yet their expressions can vary widely based on social norms.
Cultural Variation in Emotional Expression
Cultural differences significantly affect how emotions are expressed.
For instance, the expression of sadness varies:
In some cultures, individuals cry openly.
In other cultures, people suppress tears and grieve silently.
While the emotional experience remains consistent, the manner of expression diverges.
Differentiating Adaptations from By-Products
Not all characteristics are adaptations; some are by-products.
By-product: A feature that accompanies an adaptation but lacks a direct function.
Baby cuteness motivates parental care, while kitten cuteness serves as a by-product of adaptations related to recognizing babies as endearing.
Functions of Emotion
Remember: Emotions benefit both the self and social relationships.
Intrapersonal and Interpersonal Functions
Intrapersonal functions: These emotions operate within the individual, aiming to ensure survival.
Many negative emotions (e.g., disgust) are protective despite feeling unpleasant.
Interpersonal functions: These emotions govern social interactions.
Example: Embarrassment encourages forgiveness.
Limits of the Intrapersonal Focus
An exclusive focus on intrapersonal functions may not fully explain all emotional responses; emotions like love, pride, or shame encompass broader social implications.
The Ultrsocial Nature of Humans
Humans are inherently social creatures.
Social groups play a vital role in survival due to offering resources like food and protection.
Example: Hunter-gatherer societies relied on collaboration for hunting and food sharing.
Social Functions of Emotion
Humans thrive in group settings as highly social beings.
Emotions foster trust and cooperation, essential for successful social interactions.
Without social emotions, human societal structures would fail.
The Role of Love
Love serves as a significant social function by creating bonds.
Parental love drives caretaking behaviors.
Romantic love enables the formation of familial units.
Love promotes commitment and cooperation among individuals.
Embarrassment and Social Repair
Embarrassment indicates regret over mistakes, serving as a social function to mend relationships.
This emotion enhances trust and increases the willingness of others to forgive.
Indirect Social Functions
Social emotions do not provide direct resources such as food or shelter.
Instead, they protect interpersonal relationships which later materialize into survival benefits.
Example: Friends often share food when one is ill.
Dual Functions of Emotions
Certain emotions possess dual functions.
For instance, anger can serve both to protect resources intrapersonally and to signal social boundaries interpersonally.
Implications of Anger
Anger at a Thief: Protects one’s belongings (intrapersonal function).
Anger at a Friend: Can lead to an apology (interpersonal function).
The Role of Evolution in Contemporary Theories
The Evolutionary Perspective remains crucial.
While modern theories acknowledge the adaptive nature of some emotions, debate persists regarding which emotions are adaptive and how they assist in survival.
Theories Explained
Theory 1: Signal Value of Feelings
Emotions function as internal signals, guiding behavior prior to cognitive evaluation.
They affect thought processes and decision-making, illustrated by the Affect Infusion Model.
Examples:
Guilt signifies a breach in moral conventions, spurring reparative actions.
Moods can influence judgments: positive moods favor risk-taking while negative moods cultivate caution.
Theory 2: Approach and Avoidance
The brain operates through two primary systems:
Approach system: Directs behavior toward beneficial stimuli (food, mates, allies).
Avoidance system: Focuses on evading harmful threats (predators, toxins).
Theory 3: Superordinate Neural Programs
The brain can be likened to a computer: input → process → output.
Emotions function as overarching programs that control bodily systems.
Theory 4: Phylogeny of Emotions
Emotions possess a familial lineage.
New emotions emerged from older ones, with basic emotions evolving into more complex emotional responses (e.g., pride, guilt).
Challenges in Testing Evolution
Assessing emotions through an evolutionary lens is complex.
Direct observation of past evolution is not feasible.
Employing Indirect Evidence
Researchers gather indirect evidence through
Universality among humans.
Studies on animals.
Testing the adaptive roles of emotions.
The Comprehensive Nature of Emotion
Emotion = feelings + physiology + behavior + appraisals.
Fear Example
Fear = sweaty palms (physiology) + fleeing (behavior) + "this is dangerous" (appraisal) + feeling scared (emotion).
Testing Evolutionary Hypotheses
As direct observation of historical evolution is impossible, researchers test hypotheses by:
Examining emotional universals across various cultures.
Comparing human emotions with those of animals.
Formulating predictions and subjecting them to scientific scrutiny.
Example of Universality
Research by Levenson & Ekman (1992) showed similarities in physiological responses to emotions between individuals from the USA and Indonesia.
A noted limitation is that differences in response intensity could stem from task complexity rather than weaker emotional reactions.
Cultural Variation in Emotions
Adaptations can manifest differently in various cultures.
Food cravings: preference for meat in one region, dairy in another, and avocados in yet another—each reflecting a shared underlying system.
Summary of the Evolutionary View
Emotions can be perceived as adaptations or by-products of adaptations.
They resolve both survival and social dilemmas.
Evolution elucidates WHY we possess emotions, whereas culture informs HOW these emotions are expressed.