Cultural Evolution

Psychology 448C

10.1.08

Agenda

• Lecture and film clip

• In-class exercise

• Discussion

Where does cultural variation come from?

• Ecological and geographic variation (Diamond, 1997)

– Different kinds of food are afforded by varying ecologies

Film Clip: “Guns, Germs, and Steel”

Mechanisms of cultural variation

• Transmitted culture (Buss)

– People bring their ideas with them, spreading past initial set of geographic conditions

• Evoked culture (Tooby & Cosmides, 1992)

– Situations trigger innate behaviors– Ex: Selecting attractive mates is most

common in parasite-prevalent environments

What can psychologists contribute?

• Historians study “causal influences” over long periods of time and often indirect relations between events

• Psychologists study “causal influences” that are more immediate, reflecting an individual’s behavior

How do ideas catch on?

• Ideas usually need to be communicated in order to spread. They spread within social networks, so some ideas vary across groups.

• Dynamic Social Impact Theory– The frequency of interpersonal interaction

influences the transmission of ideas.

Example

• Do students’ attitudes “cluster” as a result of living in dormitories?– Randomized hall assignment– Measured attitudes at 2 weeks and 13 weeks

• All attitudes showed an increase in clustering over the term.

• … especially for the attitudes rated as more important - these attitudes were discussed more.

• New subcultures were formed on the basis of the ideas that people regularly communicated.

Increase in Clustering of Attitudes

How do Ideas Catch On?

• Ideas usually need to be communicated in order to spread. They spread within social networks, so some ideas vary across groups.

• Ideas that convey useful information are spread (e.g., razors in Halloween candy).

How do Ideas Catch On?

• Ideas usually need to be communicated in order to spread. They spread within social networks, so some ideas vary across groups.

• Ideas that convey useful information are spread.

• Emotional ideas spread.

Did you hear the one about…

• Emotional intensity of a story predicts whether people will relay it to others (Heath et al., 2001).– Mild disgust: “Before he drank his soda he saw that there was a

dead rat inside.”– Moderate disgust: “About halfway through he saw that there was

a dead rat inside.”– Strong disgust: “He swallowed something lumpy and saw that

there was a dead rat inside.”

• Participants were more likely to pass along stories that elicited strong emotions.

Likelihood of Passing Story Along

How do Ideas Catch On?

• Ideas usually need to be communicated in order to spread. They spread within social networks, so some ideas vary across groups.

• Ideas that convey useful information are spread.

• Emotional ideas spread.• Minimally counterintuitive ideas spread.

Example

• Participants received a list of 18 intuitive and counterintuitive items to read (Norenzayan

et al., 2006).• Ps were randomly assigned to 4

conditions:– Entirely Intuitive (100% intuitive)– Minimally Counterintuitive (72% intuitive)– Equal Frequencies (50% intuitive)– Maximally Counterintuitive (28% intuitive)

Sample Items

Three minutes after reading the items, participants were asked to recall them.

One week later, participants were again asked to recall the items.

Minimally counterintuitive ideas

• Over time, narratives that include a few, but not too many, counterintuitive items are recalled better.

• This is true of most religions, myths, and successful folk tales.

Some of Grimm’s Folk Tales

Cultures change

• Americans today behave differently than they did during World War II (Putnam, 2000)

People are Participating Less in Civic Affairs

People are Attending Church Less

People are Entertaining Less at Home

Families Eat Together Less Often

People are Socializing Less

People are Becoming Less Trusting

People are Becoming Less Law-Abiding

Some Causes

• Increased time pressures from families with dual incomes

• Suburban lifestyles

• Electronic entertainment

• Living through WW2

Cultures persist

• Early conditions have disproportionate influence on cultural evolution – Quakers in Philly versus Puritans in Boston

• Cultural adaptations are constrained by previously existing structures– Bat wings evolved from arms– Baseball in Japan

Cultural Psychology Studies

• Most of the studies in cultural psychology reflect the persistence of culture

• Cultural change is more often pursued by sociologists, political scientists, and economists