Twin Studies: Nature vs. Nurture

Twin Studies

• The purpose of twin studies is to determine the role of genetics, particularly using observation rather than self-reporting.
• Findings from observation largely aligned with prior self-report study conclusions about genetics.
• Earlier studies might have been affected by contrast effects, with subjects familiar with the twins comparing their actions and emotions.
• Non-shared environment has a slightly greater influence than the shared environment.
• Twin studies are valuable for examining the impacts of nature and nurture, as identical twins have the same genetics and environment.
• Fraternal twins only share the same environment, making twin studies an ideal way to study the interplay between nature and nurture.
• Additional twin study approaches include studying twins reared separately or creating divergent environments for twins with similar genes.
• Ethical considerations could come into play when researchers intentionally separate twins or cause physical or emotional harm.

Evolutionary Explanations for Gender Differences

• Disparities are related to differences in high vs. low investing partners, which is typically emotional infidelity for women but sexual infidelity for men.
• Gender also influences mate preference, jealousy, and aggression.

Evolutionary Theory and Personality

• Evolutionary psychology examines how species survival has shaped human behavior and personality.
• Adaptation, reproduction, and survival influence behaviors exhibited by humans to this day.

Evolutionary Perspective and Sexual Orientation

• It is linked by the kinship hypothesis (helpers in the nest) and the tipping point hypothesis (gay allele).

Shared vs. Non-Shared Environment

• A shared environment includes similar environmental elements that can affect people in similar ways.
• Non-shared environment refers to experiences or situations specific to an individual contributing to differences.

Evolutionary Adaptations & Personality

• Behaviors can be seen as adaptations to evolution, as they develop by enhancing survival and lessening reproductive stress.
• Adaptive behaviors aid in response to environmental challenges like avoiding danger.
• These behaviors influence personality, as behaviors adaptive in humanity's evolutionary past contributed to the development of personality traits.
• Cooperative or cautious behaviors might evolve into traits like agreeableness.
• Evolutionary pressures can affect behavioral traits by forming a genetic predisposition.

Behavioral Genetics

• The goal is to determine the percentage of attributes linked to genetics and the contributions of the environment.
• This involves studying the interactions between genes and the environment and pinpointing significant aspects of the environment.
• Methods include selective breeding, family, twin, and adoption studies.

Heritability Coefficient

• The heritability coefficient measures the proportion of observed variance attributable to genetics.
• The formula for calculating the heritability index, using the classical twin study design, is H² = 2(rMZ - rDZ).

Shared and Non-Shared Environmental Influences

• Family environment and educational environment can influence traits like empathy, agreeableness, and social conformity.

Natural Selection vs. Sexual Selection

• Natural selection involves adaptations along with changes that occur over time.
• Sexual selection entails traits that evolve especially through mating success, where inclusive fitness theory is applicable.

Additional Concepts

• Kinship hypothesis supports species survival.
• The gay allele of homosexuality indicates a genetic component.
• Fitness increases when helping relatives survive and thrive.
• Genetics influence personality, proven through twin and adoption studies.
• Genetics account for 30-70% of personality; shared/non-shared environment can also have an influence, including measurement error.
• Mate selection is linked to personality psychology, with different personalities seeking specific qualities in mates, such as high or low commitment.

Personality as a Product of Evolution

• Personality traits evolved as adaptive strategies that aided in survival threats (neuroticism), working together (agreeableness), and exploring, innovating, and leading.

Biology, Psychology, and Personality

• Personality is influenced by biological processes in the brain.
• Systems of hormones impact personality through long-term mood changes.

Dopamine and Serotonin

• Dopamine (extraversion, openness) relates to reward and pleasure, which is possibly related to bipolar disorder, extraversion, and impulsivity.
• Serotonin (Neuroticism, Conscientiousness, Agreeableness) relates to behavioral inhibition to impact mood stability.

Brain Activity Measurement

• EEG is the test used to identify when the brain is active using electrodes.
• Limitations exist, as electrodes have limited reading capabilities.

Hebb's Theory of Optimal Arousal

• People perform best when their arousal level is neither too high nor too low.
• A slightly different level exists at which each individual perform best.

Personality Dynamics and Defense Mechanisms

• Reaction Formation involves unconsciously replacing a feeling/thought/emotion with its opposite, often exaggerated (Ex: Someone secretly jealous of their friend expressing praise).
• Projection involves attributing one's negative thoughts/feelings to others.
• Denial involves refusing to acknowledge a painful situation or fact.
• Displacement involves redirecting emotions from the source onto another, safer target (Ex: A parent upset with their boss taking frustrations out on their family.).
• Repression involves pushing painful thoughts or emotions (memories) back into the unconscious.
• Regression involves retreating to an earlier developmental stage (Ex: An older child throwing a tantrum or wanting to be held and comforted by their parents.).
• Rationalization involves creating a logical but incorrect explanation to rationalize the mistake.
• Sublimation involves taking a negative impulse and changing it into something more socially acceptable (Ex: Channeling aggression into sports)

Research Behind Mechanisms

• Defense mechanisms realign our thinking to safeguard our self-perception rather than our ego.
• Reaction formation was measured in 2 research scenarios, including women high on sex guilt being exposed to erotica, measuring how they assessed philosophically.
• Homophobic men were shown interactions showcasing homosexual behavior, their sexual arousal was measured.
• People were administered bogus feedback regarding personality test results; the test subjects were instructed to rate those around them.
• A stage in Kubler Ross' response to diagnosis is denial, people tend to be unrealistically optimistic.

Psychosexual Stage Theory Aspects

• Physical focus, psychological theme, and adult character type are the aspects.
• Anal stage is about learning the sensations of having to go and dealing with sensations appropriately.
• Phallic stage is about coming to terms with sex differences and implementing the stages appropriately.
• Reaction formation is a defense mechanism where a person expresses the opposite of their true feelings, often highly exaggerated.

Mental Energy Types

• Libido is related to sexual drive (life-affirming instincts).
• Thanatos refers to the death instinct (self-destructive instincts).

Motivation

• Internal motivation is driven by desires, and external motivation is driven by rewards and societal pressures.

Psychoanalysis

• Psychoanalysis studies individuals within their preconscious, conscious, and unconscious.
• It focuses on behaviors and the likelihood that those stimuli stem from unconscious thoughts and wants.

Levels of Consciousness

• The three levels of consciousness are conscious, preconscious and unconscious.
• Conscious: aware of.
• Preconscious: can be retrieved
• Unconscious: hidden

Theories of the Mind

• Id: Present at birth; source of all drives and urges (Ex: "I want to skip my workout because I feel lazy and just want to relax.")
• Ego: Constrains the id from reality (Ex: "I shouldn't skip the workout because it's essential for my health and discipline.")
• Superego: Internalizes values, morals, and ideals of society (Ex: "I can do a shorter workout today and make up for it with a longer session tomorrow.")
• The Ego negotiates between the impulsive Id and the judgmental Superego, often using defense mechanisms to reduce conflict or anxiety.

Psychosexual Development Stages

• Oral Stage - Dependency (Ex: smoking), aggression
• Anal Stage - Obsessively tidy or un-tidy
• Phallic Stage - Vanity/envy, sexual dysfunction
• Latency Stage Genital Stage

Psychoanalysis

• It is a method of psychotherapy by deliberately restructuring personality.

Process of Psychoanalysis

• Interpretations occur as an element
• Insight occurs throughout the process
• Resistance can occur during the process
• Transference can occur during the process
• Repetition compulsions

Freud vs. Erikson Stages

• Freud's stages do not facilitate life-long ability to work toward completing or overcoming trauma , unlike Erikson's stages.
• In Erikson’s stages, people can adapt and work through life challenges.
• Erikson's stages have a much heavier social focus than Freud's stages.

Karen Horney

• Horney was inspired by Freud in the opposite direction: she believed that men envied women's ability to have children.
• Horney believed this creates conflict between sexes, that leads to women “devalued and become an object of purely physical needs."

"Locked-In" vs. "Locked-Out" Crisis

• Locked-in crisis- feeling trapped in a role of obligations, commitments, or perceived limitations (ex: Relationship, job, parents)
• Locked-out crisis- feeling behind in life and unable to achieve certain goals (ex: Career).

Imagination Inflation Effect

• The imagination inflation effect involves recalling memories in an exaggerated or inaccurate way.
• This could influence false memory due to repressed memories undergoing the inflation effect.

Bowlby's Theory of Attachment

• Three types of infant attachments: secure, avoidant, and ambivalent.
• Secure attachment- kids should be only a little upset when a guardian leaves and happy when they return.
• Avoidant/ Ambivalent- extreme reactions.
• Secure attachment - strong trust, actively seek help/support, needs met as a child.
• Avoidant attachment - strong need for independence, uncomfortable with intimacy, difficulty being vulnerable, inconsistent/neglectful care.
• Ambivalent (anxious) - strong desire for closeness, very anxious about abandonment/rejection, clingy/need extra reassurance/struggle with trust, inconsistent/unresponsive care.

Adult Attachment Styles

• Early bonds with parents influence later relationships.
• Attachment styles influence how individuals communicate their needs/feelings and interpret their partner's behavior.
• Secure attachments lead to long, healthy relationships, whereas avoidant/ambivalent attachments more likely to lead to relationship conflict/instability

Issues with the MMPI-2

• Designed and used on non-Indigenous, white populations; can cause issues.
• Cultural mismatches- some items may be misunderstood, interpreted differently.
• Tools without cultural adaptation lead to inaccurate results or harmful conclusions.
• Clinicians should adapt existing assessments or develop new ones with Indigenous communities to ensure validity and relevance.

Social Construction of Race

• Meaning race is derived from a political, cultural, and environmental aspect; there is no race gene in our DNA.

"Science of Race"

• The concept behind it is that race is biologically determined and that some groups are inferior to others.
• This contributed to the justification of social hierarchy.