Foundations of Emotion

Why do we feel?

• To prompt us to respond to our environment (fight/ flight)
• Reinforces pro-social behaviour
• Reaction to violation of social norms
• Provides feedback on our experience

What are emotions?

Responses to the success or obstruction of our goals.

“A brief, specific response, both psychological and physiological, that helps people meet goals, including social goals.”

– Gilovich, et al. (2024)

Emotion & Motivation

Motivation = the driving force behind action

• Emotions are motivating forces
  • Hunger prompts you to eat
• Emotion gives meaning to our experiences

Characteristics of Emotions

Brief

• Facial expressions last 1-5 seconds
• Physiological responses last a few minutes
• Emotional episodes = brief
• Moods = last longer

Specific

• Direction at specific people, objects, events

Motivate Behaviour

• Emotions are tools shaped by evolution to guide behaviour
• “Evolution’s executioners” – Robert Wright
• Guidance not always helpful

Social

• Emotions support adaptive functioning in social interactions

Anger -> addresses violations of social norms

Guilt -> regulates behaviour to avoid damaging relationships

Awe -> connects us to something larger

Embarrassment -> appeasement

Emotions vs Moods

Emotion	Mood
A brief, specific psychological and physiological response that helps people meet goals, including social goals.	An affective state lasting hours or days, less tied to specific causes and more generalised than emotions.

Evolution & Socialisation

Cultural differences in emotional experience

• Emotional experiences and expressions vary across cultures.
• What is considered pleasant/disgusting differs by culture (e.g., oysters, Parmesan cheese, fried crickets).
• Cultural norms shape emotional expression:

• Some cultures value emotional restraint (e.g., English culture).
• Others encourage emotional expressiveness (e.g., Italian culture).

Context-dependent emotional expression

• Appropriate emotional expression depends on the social context.
• Expected behaviour changes across situations:

• funerals
• customer service roles
• meetings with political leaders

Understanding contextual emotional cues helps effective social interaction.

Enculturation & Emotional Development

• Emotions are shaped through learning and cultural socialisation.
• Parents/caregivers teach emotions during early childhood.
• Adults often exaggerate emotional expressions with children.
• This helps children:

• recognise emotional cues
• imitate emotional expressions
• develop emotional understanding.

The Components of Emotion

Physiological Responses

• Emotions involve automatic bodily changes, mainly controlled by the autonomic nervous system (ANS).
• The sympathetic nervous system prepares the body for action (“fight or flight”):
  • increased heart rate
  • faster breathing
  • muscle tension
• The parasympathetic nervous system restores calm after the emotional event.
• Emotional responses also involve:
  • hormonal systems
  • brain activity
  • facial muscles and body movement
• Emotions are therefore coordinated whole-body responses.

Cognitive Processes

• Cognition influences how emotions are interpreted, labelled, and understood.
• Language shapes emotional meaning:
  • e.g., “moral disgust” may describe moral outrage rather than literal physical disgust.
• People use feelings as information when making judgments.
• Norbert Schwarz and Gerald Clore (1983):
  • Participants reported greater life satisfaction on sunny days than rainy days.
  • The effect disappeared when participants were first reminded about the weather.
• Demonstrates that:
  • incidental moods can bias judgments
  • correctly identifying the source of feelings reduces this bias.

Social and Expressive Behaviour

• Emotions are communicated outwardly through:
  • facial expressions
  • tone of voice
  • posture
  • touch
  • art and music
• Emotional expression is shaped by culture and socialisation.
• Facial expressions are especially important for emotional communication.
• Paul Ekman studied facial expressions and emotional universality.
• Research showed that smiles can differ:
  • genuine smiles involve authentic emotional engagement
  • non-genuine smiles may be socially performed or polite.

Influential Approaches To Emotion

Evolutionary Account

Darwin:

• Proposed that emotions evolve for adaptive functions
• Focused on expressive behaviour (facial expressions, gestures, postures) shared between humans & animals
• Continuity = emotional expressions have a similar purpose across humans and animals
• Universality = many emotional expression are universal
  • Ekman’s 6 basic emotions
  • Blind athletes still make the same expression after winning

James–Lange Theory of Emotion

Overview

• Proposed by William James and Carl Lange (1890).
• Suggests emotions result from perceiving bodily changes.
• Sequence:
  • stimulus → physiological response → emotion
• “We feel afraid because we tremble.”
• Focused mainly on coarse/basic emotions:
  • fear
  • rage
  • grief
  • love

Example

• Seeing a snarling dog causes:
  • increased heart rate
  • trembling
  • running away
• The interpretation of these bodily reactions produces the feeling of fear.

Key Idea: Body → Emotion

• External stimulus triggers bodily responses first.
• Emotion occurs after interpreting these physiological changes.
• Emphasises a strong connection between bodily states and emotional experience.

Core Assumptions

• Emotions are inseparable from bodily responses.
• Without physiological symptoms, emotions would not exist.
• Different emotions are linked to different bodily patterns.
• Highlights the role of the autonomic nervous system (ANS).

Implications

• People partly understand emotions through awareness of bodily states.
• Influenced modern physiological theories of emotion.
• Emphasised the importance of body–brain interaction in emotional experience.

Cannon–Bard Theory of Emotion

Overview

• Developed by Walter Cannon and Philip Bard.
• Challenged the James–Lange theory.
• Proposed that emotions and bodily responses occur simultaneously.
• Emphasised the brain’s central role in emotion.

Key Concepts

• Emotional stimulus is processed by the brain (especially the thalamus).
• The brain simultaneously produces:
  • subjective emotional experience
  • physiological arousal
• Sequence:
  • stimulus → brain processing → emotion + bodily response at same time

Example

• Seeing a snarling dog causes:
  • feeling fear
  • racing heart/body preparation
• Both occur together, not one after the other.

Core Assumptions

• Emotions originate in the central nervous system.
• Bodily feedback is not required to feel emotions.
• Physiological responses are:
  • often too slow
  • too similar across emotions
  • unable to fully explain emotional differences

Implications

• Influenced neurological approaches to emotion research.
• Positioned the brain as the source of emotional experience.
• Challenged the idea that bodily changes create emotions.

Comparing the Theories

James–Lange Theory	Cannon–Bard Theory
Bodily response comes first	Emotion and bodily response occur simultaneously
Emotion results from interpreting bodily changes	Brain generates both emotion and bodily response
Focus on peripheral bodily processes	Focus on central brain processes
“I tremble, therefore I feel fear.”	“I feel fear and tremble at the same time.”

Modern View

• Both theories contributed important ideas to emotion research.
• Modern approaches recognise that emotions involve:
  • bodily responses
  • brain activity
  • cognitive interpretation
• Emotion is now viewed as an interaction between physiological and neurological processes.

Facial Feedback: Example of a Peripheral Theory

Facial Feedback Hypothesis

Facial expressions contribute to the generaiton of emotions by sending signals to the brain.

Shows connection between physical expressions and emotional experiences.

Evidence From Research

Strack et al. (1988) conducted a study where participants held a pen in their teeth (activating smiling muscles) or lips (activating a pout, inhibiting smiling).

Participants in the “smiling” condition rated cartoons as funnier, supporting the idea that facial expressions influence emotional experience.

Note that some studies failed to replicate Strack et al’s (1988) findings, particularly when participants were aware of being observed, such as through video recording.

However, when participants were unaware of being watched, the effect was replicated, suggesting that context plays a significant role (Noah et al., 2018).

Two-Factor Theory of Emotion (Schachter & Singer, 1962)

Overview

• Developed by Stanley Schachter and Jerome Singer.
• Emotion results from:
  1. physiological arousal
  2. cognitive interpretation (labelling)
• Same bodily arousal can produce different emotions depending on context.
• Combines elements of:
  • James–Lange theory (importance of bodily arousal)
  • Cannon–Bard theory (arousal alone is not emotion-specific)

Main Idea

• Sequence:
  • stimulus → physiological arousal → cognitive label → emotion
• Example:
  • racing heart after coffee
  • stressful situation → labelled as anxiety
  • exciting situation → labelled as excitement

Key Components

1. Undifferentiated Physiological Arousal

• General bodily activation.
• Not tied to one specific emotion.
• Examples:
  • increased heart rate
  • sweating
  • shaking

2. Construal (Cognitive Interpretation)

• Person interprets the situation and labels the arousal.
• The label determines the emotion experienced.
• Context is essential for identifying emotion.

“Suproxin” Study

Procedure

• Participants told they were receiving a vitamin injection (“Suproxin”).
• Actually injected with:
  • adrenaline (epinephrine) or
  • placebo
• Some participants were informed about adrenaline effects; others were not.
• Participants then interacted with a confederate acting:
  • euphoric or
  • angry

Findings

• Participants with no explanation for their arousal adopted the confederate’s emotion:
  • euphoric confederate → participants felt euphoric
  • angry confederate → participants felt angry
• Informed participants were less influenced because they correctly attributed arousal to the injection.

Implications

• Emotions can be misattributed depending on context.
• Same physiological arousal may be interpreted differently:
  • attraction
  • fear
  • anger
  • excitement
• Demonstrates the importance of cognitive appraisal in emotion.

Simple Formula

• Physiological arousal + cognitive label = emotion

Comparison to Earlier Theories

Theory	Main Idea
James–Lange	Bodily response causes emotion
Cannon–Bard	Emotion and bodily response occur simultaneously
Two-Factor Theory	Emotion = bodily arousal interpreted using context

Disgust: Disease Avoidance Mechanism

What is Disgust?

Definition of Disgust

Distaste vs Disgust

Distaste	Disgust
Basic sensory reaction	Complex emotional/cognitive response
Triggered by unpleasant tastes (e.g., bitterness)	Triggered by contamination or offensiveness
Present in newborns and animals	Develops later in childhood (~5 years)
Reflexive and biological	Involves cognition and avoidance

Key Point

• Animals and infants may experience distaste, but full disgust appears more uniquely human because it involves contamination concepts.

Contamination Sensitivity

• Disgust strongly focuses on contamination.
• Triggered by:
  • disease cues
  • decay
  • bodily waste
• Perceived contamination matters more than actual danger.
• Example:
  • Sterilised cockroach dipped in juice still makes people reject the juice.
• Shows disgust is psychologically powerful even when people know something is safe.

Disgust as a Disease-Avoidance Mechanism

Evolutionary Function

• Disgust likely evolved to protect against disease and pathogens.
• Motivates avoidance of:
  • spoiled food
  • bodily fluids
  • contaminated objects
• Acts as a behavioural “first line of defence” before infection occurs.

Biological vs Behavioural Defences

Biological Defences

• Body fights pathogens using:
  • physical barriers
  • stomach acid
  • immune responses

Behavioural Defences

• Disgust helps avoid contamination before exposure happens.
• Provides an evolutionary survival advantage.

Disease-Avoidance in Animals

Examples

• Chimpanzees wipe off faeces to reduce contamination risk.
• Mammals and birds groom to remove parasites:
  • ticks
  • lice
  • fleas
• Grazing animals avoid eating near faeces.
• Animals move away from dirty nesting areas.
• Some species self-medicate with plants:
  • e.g., dogs and cats eating grass

Key Point

• Animal behaviours suggest an evolved disease-avoidance system across species.

Disease-Avoidance in Humans

• Humans are highly sensitive to contamination cues:
  • bodily fluids
  • spoiled food
  • signs of illness
• Val Curtis and Biran (2001):
  • found disgust elicitors involved in transmission routes of infectious diseases.
• Disease-relevant images are rated as more disgusting than similar non-disease images.

Overall Conclusion

• Disgust functions as an evolved pathogen-avoidance mechanism.
• Helps reduce exposure to disease by motivating avoidance behaviour.

Sympathetic Magic & Disgust

Overview

• James George Frazer (1890) described “sympathetic magic”:
  • intuitive belief systems that shape disgust reactions.
• Disgust is influenced not only by real danger, but also by beliefs and mental associations.
• Two major principles:
  1. Law of Similarity
  2. Law of Contagion

The Law of Similarity

Definition

• Things that resemble each other are treated as if they are actually the same.

Example

• People may feel disgusted by chocolate shaped like faeces even though they know it is safe to eat.

Key Idea

• Appearance alone can trigger disgust.
• The brain links the object to contamination because it looks similar to something disgusting.

Implication

• Harmless objects may be avoided purely because of visual resemblance.

The Law of Contagion

Definition

• Once two things come into contact, they are mentally linked permanently.

Example

• People may avoid a sterilised fork previously used by a sick person despite knowing it is clean.

Key Idea

• Contact with contamination is seen as leaving a lasting “essence” behind.
• People overestimate contamination risk even when no real danger exists.

Implication

• Disgust spreads through association, not logic.

Disgust Without Real Threat

Overgeneralisation

• Disgust responses often continue even when people know there is no genuine threat.
• Supported by research from Paul Rozin et al. (1986).

False Positives

• Disgust system is biased toward “false positives”:
  • better to mistakenly avoid something harmless
  • than fail to avoid a real pathogen

Result

• Minimal or symbolic contamination cues can trigger strong disgust.
• Disgust is deeply ingrained and resistant to reasoning.

Overall Conclusion

• Sympathetic magic explains why disgust can appear irrational.
• Human disgust overgeneralises contamination through:
  • similarity
  • contact
  • symbolic association.

Measuring Disgust

Disgust Elicitors = specific objects, substances or situations that provoke a disgust response. Often linked to things that could carry disease.

Classic Disgust Elicitor:

• spoiled food
• vomit
• bodily fluids

Disease relevant vs clean object:

• dirty tissue vs clean tissue

Sterilised but still disgusting:

• sterilised cockroach

Individual Differences in Disgust

Measuring Disgust Sensitivity

• Psychologists use self-report questionnaires to measure disgust sensitivity.
• Major scales:
  1. Disgust Scale (DS)
  2. Three-Domain Disgust Scale (TDDS)
• These scales assess:
  • how sensitive someone is to disgust
  • which types of disgust affect them most strongly.

Disgust Scale (Haidt, McCauley, & Rozin, 1994)

Overview

• 32-item questionnaire measuring disgust across 7 domains:
  • body products
  • body envelope violations
  • hygiene
  • animals
  • food
  • death
  • sex
• Also measures beliefs linked to sympathetic magic:
  • contagion
  • similarity

Important Finding

• Moral disgust items were removed because they did not strongly correlate with overall disgust sensitivity.
• Suggests moral disgust may differ from core pathogen-related disgust.

Sample Domains & Items

Domain	Example
Body products	Seeing someone vomit
Animals	Seeing a rat run across your path
Hygiene	Avoiding touching public toilet seats
Magic/Contagion	Sleeping in a hotel room where someone died
Sex	Sexual acts involving animals
Envelope violations	Seeing exposed intestines
Food	Smelling spoiled milk
Death	Touching cremated ashes

Three-Domain Disgust Scale (Tybur et al., 2009)

Overview

• 21-item questionnaire.
• Measures 3 domains of disgust:
  1. pathogen disgust
  2. sexual disgust
  3. moral disgust

Sample Items

Domain	Example
Pathogen	Stepping on dog poop
Sexual	Hearing strangers having sex
Moral	Cutting in line for tickets

Associations with Disgust Sensitivity

Gender Differences

• Women generally show higher disgust sensitivity than men.

Moral Disgust

• Moral disgust subscale has limited validity.
• Bunmi Olatunji et al. (2012):
  • questioned whether moral disgust reflects the same construct as core disgust.

Psychological Associations

Higher disgust sensitivity is linked with:

• obsessive–compulsive symptoms
• perceived vulnerability to disease
• neuroticism
• political conservatism

Lower disgust sensitivity is linked with:

• sensation seeking

Overall Conclusion

• Disgust sensitivity varies across individuals.
• It is connected to personality traits, beliefs, behaviour, and mental health tendencies.

The Source Effect for Disgust & Disease-Avoidance

Overview

• Trevor Case, Richard Stevenson, and Val Curtis (2009) proposed the “source effect” in disgust.
• Key idea:
  • disgust depends not only on the contaminant itself
  • but also on who or what the contaminant comes from.
• Same contaminant can produce different disgust reactions depending on familiarity.

Strangers & Pathogens

Main Idea

• Disgust system must be flexible to balance:
  • disease avoidance
  • caregiving/social bonding

Evolutionary Logic

• Strangers are more likely to carry novel pathogens.
• Familiar people share similar microbial environments, reducing perceived risk.

Prediction

• Same contaminant = stronger disgust if it comes from an unfamiliar source.

Example

• Sharing a toothbrush with:
  • stranger → highly disgusting
  • romantic partner → less disgusting

Key Point

• As familiarity decreases, disgust increases.

Maternal Disgust Study (Case et al., 2006)

Research Question

• Can mothers reduce disgust responses toward infant faeces to allow caregiving?

Method

• Mothers rated disgust toward:
  • their own baby’s dirty nappies
  • another baby’s dirty nappies
• Included:
  • self-report ratings
  • lab-based tests with actual nappies

Findings

• Mothers consistently rated their own baby’s nappy as less disgusting.
• Effect remained even when mothers did not know which nappy belonged to their child.

Conclusion

• Source familiarity reduces disgust responses.

Role of Exposure

Key Finding

• Repeated exposure appears to reduce disgust through habituation.
• Familiarity weakens the disgust response over time.

Evidence

• Workers regularly exposed to:
  • bodily waste
  • garbage
  • cadavers
    often report reduced disgust sensitivity.

Important Point

• Exposure plays a larger role than conscious labelling alone.

Generalising the Source Effect

Disease-Avoidance Explanation

• Close others are perceived as lower pathogen risks.
• Unfamiliar individuals trigger stronger disgust because they may carry unfamiliar diseases.

Example

• Your own dog’s faeces may feel less disgusting than an unknown dog’s faeces.

Adaptive Function

• Helps balance:
  • social attachment
  • caregiving
  • self-protection from disease

Overall Conclusion

• Disgust is flexible rather than fixed.
• Familiarity and repeated exposure reduce disgust responses.
• Source effect supports the disease-avoidance theory of disgust.

Difficulties for the Disease-Avoidance Account

Sexual behaviour & disgust

• Sex involves direct & prolonged exposure to bodily fluids
• Should trigger disease avoidance, yet this context is an exception
• Shows conflicting responses can be reconciled

Developmental Emergence of Disgust

• Disgust remeges quite late in development compared to other basic emotions
• Expression of disgust depends on cognitive development, learning, socialisation

Moral Disgust

• People can experience disgust in reponse to moral violations
• Challenges the idea that disgust is always related to disease

Disgust in Animals

• Not all animals exhibit disease avoidance disgust
• It is uniquely human

Sexual Arousal and Disgust

Overview

• Sex challenges the disease-avoidance theory because it involves:
  • bodily fluids
  • close physical contact
  • potential pathogen exposure
• If disgust always prevented contamination, sexual behaviour should trigger strong avoidance.
• Richard Stevenson, Trevor Case, and Val Curtis (2011) investigated this issue.

The Study

Method

Participants were randomly assigned to view:

• erotic images
• images of clothed women
• positively arousing images (e.g., skydiving)
• negatively arousing images (e.g., weapons)

After Viewing

Participants rated disgust toward:

• sex-related disgust stimuli:
  • sexual images
  • sexual audio
  • handling condoms
• non-sex-related disgust stimuli:
  • pollution
  • vomiting sounds

Findings

Main Result

• Sexual arousal selectively reduced disgust toward sex-related stimuli.
• Responses to non-sex-related disgust stimuli remained unchanged.

Key Point

• Participants did not become generally less disgust-sensitive.
• Instead, disgust was reduced only in contexts relevant to sexual behaviour.

Conclusion

• Sexual arousal creates context-specific modulation of disgust.

Implications

Disease-Avoidance Perspective

• Disgust system remains active overall.
• It becomes temporarily flexible when disgust conflicts with reproduction.

Adaptive Function

• Allows balance between:
  • pathogen avoidance
  • sexual reproduction

Broader Implications

• Helps explain risky sexual behaviour.
• Suggests emotional systems can adapt depending on motivational priorities.

Late Emergence of Disgust

Overview

• Disgust develops later than many other emotions (e.g., fear).
• Young children often show little aversion to contamination-related stimuli.
• Raises questions about how disgust develops within a disease-avoidance framework.

Study on Development of Disgust

Researchers

• Richard Stevenson, Oaten, Case, Repacholi, and Wagland (2010).

Method

• Parents reported children’s disgust reactions.
• Children aged 2–15 years were asked whether they wanted to:
  • see
  • touch
  • smell
    various stimuli.

Stimuli Included

• core disgust elicitors:
  • dirty socks
  • organic fertiliser
• animals:
  • maggots
• sociomoral scenarios

Measures

• behavioural avoidance
• negative evaluations
• facial expressions of disgust

Findings

Developmental Sequence

Disgust sensitivity emerged in stages:

1. Core disgust elicitors first
2. Animal-related disgust next
3. Sociomoral disgust later

Important Observation

• Some young children avoided core disgust stimuli before fully understanding contagion.

Implications

Role of Learning & Cognition

• Late emergence suggests disgust is shaped by:
  • learning
  • cognitive development
  • conceptual understanding

Support for Disease-Avoidance Theory

• Early avoidance of core contaminants suggests some disgust mechanisms develop before full cognitive understanding of contamination.

Moral Disgust

Overview

• People often report feeling disgust toward moral violations:
  • lying
  • cheating
  • betrayal
• These behaviours do not involve direct contamination or disease threat.
• Creates a challenge for the disease-avoidance theory:
  • why would a pathogen-avoidance emotion respond to abstract social behaviours?

Research Approaches

Common Methods

Researchers study moral disgust using:

• self-report measures
• morally relevant scenarios:
  • unfairness
  • norm violations
• disgust inductions before moral judgement tasks

Goal

• Examine:
  • subjective experience of disgust
  • effect of disgust on moral evaluation

Key Findings

• People frequently describe moral violations as “disgusting.”
• Induced disgust can lead to harsher moral judgements.

Critiques of Moral Disgust

Trevor Case, Val Curtis, and Richard Stevenson (2012) argued moral disgust:

• weakly correlates with core disgust domains
• differs in intensity and developmental pattern
• may not habituate like pathogen disgust
• remains intact in Huntington’s disease while core disgust decreases
• may function more as a metaphor for moral outrage

Methodological Issue

• Studies often confound:
  • core disgust
  • moral disgust
• Example:
  • “eating your dog” combines contamination and moral violation.

Main Conclusion

• Moral disgust may differ from core pathogen-related disgust.
• Could represent:
  • a related emotional system
  • or moral outrage expressed metaphorically as “disgust.”

Key Debate

• Is moral disgust:
  • the same disgust system extended socially?
  • or a conceptually different emotional response?

Disgust in Animals

Overview

• If disgust evolved for disease avoidance, similar behaviours should appear in animals.
• Based on Charles Darwin’s idea of evolutionary continuity.
• Research on animal disgust has increased only recently.

Research on Great Apes

Findings

Trevor Case et al. (2020):

• Great apes show some aversion to classic disgust triggers:
  • faeces
  • spoiled food
• Example:
  • chimpanzees interrupt eating to clean faeces off themselves.

Important Limitation

• Ape disgust is weaker and more limited than human disgust.
• Apes may ignore:
  • blood
  • sick group members
• May consume contaminated food once visible contamination is removed.

Human vs Ape Disgust

Humans

• Avoid:
  • invisible contamination
  • imagined contamination
  • symbolic contamination
• Disgust shaped by:
  • culture
  • cognition
  • abstract reasoning

Great Apes

• Responses mainly based on direct sensory cues:
  • smell
  • sight
• Less evidence for abstract contamination beliefs.

Evolutionary Perspective

• Some rudimentary disgust exists in animals.
• Human disgust is far more flexible and cognitively complex.

Human Disgust Involves

• imagination
• memory
• cultural learning
• symbolic thinking

Overall Conclusion

• Human disgust extends beyond immediate sensory threats.
• Suggests disgust is partly evolutionary and partly shaped by advanced cognition and culture.