Personality part 2 (week 10)

What is the nature vs. nurture debate in personality?

The debate centers on whether personality traits are primarily shaped by genetic inheritance (nature) or environmental factors (nurture).

How are twin studies used to understand personality?

By comparing monozygotic (identical) and dizygotic (fraternal) twins reared together or apart, researchers can estimate genetic and environmental influences on personality.

What are monozygotic twins?

Monozygotic twins come from the same egg, share 100% of their genes, and are genetically identical.

What are dizygotic twins?

Dizygotic twins come from two separate eggs, share about 50% of their genes, and are genetically similar like ordinary siblings.

What is the significance of comparing twins reared together vs. apart?

It helps separate the effects of shared environment from genetics, allowing clearer analysis of nature vs. nurture.

What have twin studies shown about the Big Five traits?

About 40% of variance is genetic, 25% from shared environment, and 35% from non-shared environment; extraversion appears least influenced by shared environment.

What did Borkenau et al. (2001) find about genetic influence on personality?

They found that personality traits show around 40% genetic influence using observational methods and twin comparisons.

What are some surprising correlations found in identical twins reared apart?

Similarities in time spent watching TV, number of childhood accidents, religious attitudes, divorce patterns, and even happiness.

How similar are adopted siblings compared to biological siblings?

Adopted siblings are no more similar than two randomly selected children; biological siblings show more similarity, suggesting a genetic role.

What limitation is illustrated by the identical twin anecdote about neatness?

It shows that different life narratives can explain the same personality trait, illustrating the challenge in isolating environmental causes.

What are psychodynamic theories of personality?

They emphasize instinctive, unconscious motives (e.g., Freud's theories) as drivers of personality.

What are social-cognitive theories of personality?

These theories highlight beliefs about the world, such as locus of control and self-efficacy, as shaping personality.

What is locus of control according to Rotter?

It refers to whether a person believes control over life events lies within themselves (internal) or with external forces (external).

What is self-efficacy according to Bandura?

It is a person’s belief in their ability to succeed in specific situations or accomplish tasks.

What is the cognitive-affective personality system (CAPS)?

A theory by Mischel & Shoda focusing on how people’s encoding, beliefs, goals, and emotions interact with situations to produce behavior.

What are common biases in self-report personality measures?

People may present themselves in socially desirable ways, lack self-awareness, or interpret questions subjectively.

What are informant-report and observer-report methods in personality assessment?

Informant-report relies on others’ perceptions (e.g., friends), while observer-report uses trained observers during behavior assessments.

What’s a potential problem with comparing adopted siblings to twins in research?

Adopted siblings may experience unique environments not controlled in the study, and their lack of genetic relation limits conclusions about heredity.

What is the conclusion of most twin studies regarding personality?

Personality is influenced by both genetics and environment, but neither fully explains individual differences on its own.