Unit IV – Nature vs. Nurture: Environmental Influence Background Individual variations in personality is 40% to 50% genetic The rest? Parental influence? ~10% The rest? Many theories, but unknown Four major environmental influences

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 1) Prenatal environment Influences in womb major influence Health, nutrition, toxic agents, etc. 2) Early Experience & Brain Development Early experience can help or hinder brain development More positive stimulus (education, etc.), more developed brain, especially cerebral cortex Less - opposite is true Impoverished environment Rat brain cell Rat brain cell Enriched environment

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 3) Peer influence Often more influential than parents More time spent with peers than parents Selection effect We seek out peers with similar attitudes and interests

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Behavior, ideas, attitudes, traditions shared by a large group of people Transmitted from generation to generation More homogeneous the ethnic groups; cultural less relevant, genetics more important (heritability) Example Japan/Iceland – extremely homogeneous culture, so genetic differences more evident

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Variations Across Cultures When part of a culture, we don’t notice When in a different culture, that’s when we notice culture

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Variations Across Cultures terms Norms Understood rule for accepted behavior Varies from culture to culture

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Variations Across Cultures terms Example of norms Personal space Buffer zone we like to maintain around our bodies Differs from culture to culture

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Variations Across Cultures terms Example of norms Fine in the US Not so in the former Soviet Union

Unit IV – Nature vs. Nurture: Environmental Influence Four Major Environmental Influences 4) Culture Variations Across Time Culture changes over time What’s acceptable now, may not be in ten years Example: Hats in buildings

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nature Looking at gender as a major example of nature vs. nurture Sex determined by your 23rd pair of chromosome X chromosomes Found in both males & females From mother Y chromosome Found only in males From father Females: XX Males: XY

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nurture Gender role Role Set of expectations (norms) about a social position How a type of person should act/behavior Example: How a teacher should act, how a football player should act, etc.

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nurture Gender role Our expectation how men and women should behave Society assigns each one of us to a gender Gender Social category of male and female This results in: Gender identify: our sense of being male and female

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nurture Gender Social category of male and female This results is: Gender identify: our sense of being male and female Gender-typing: acquisition of traditional masculine or feminine roles

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nurture Theories of Gender Typing 1) Social learning theory Theory that we learn social behavior by: -being rewarded or punished Mostly unconscious Examples: Billy is yelled at for playing with his sister’s dolls. Doesn’t do that again.

Unit IV – Nature vs. Nurture: Nature and Nurture of Gender Nature and Nurture of Gender: Nurture Theories of Gender Typing 2) Gender schema theory Social learning theory plus cognition We learn what gender role for our gender - observation Adjust our behavior accordingly Schema Concept or framework that organizes and interprets information Based on past experience Example Based on your past experience, boys play football and girls do gymnastics