Evolution and Human Behavior

Chapter Study Outline

1. Why Is Evolution Relevant to Behavior?
   1. Behavioral traits are phenotypic and reflect interactions between genes and the environment.
      1. The nature–nurture debate assumes that there are clear distinctions between the influence of genes and the influence of the environment.
      2. Traits developed in response to environmental cues are said to be plastic rather than canalized.
      3. Adaptive behavior traits can be affected by natural selection in different environments.
2. How We Think
   1. Natural selection determines the types of problems that any one species is good at solving. Rats, for instance, know what kinds of food to avoid.
   2. Environment of evolutionary adaptedness (EEA)
      1. The human brain was designed for life in foraging societies, where food sharing is important.
      2. Humans can find out who in their group cheat in terms of social contracts.
      3. Was there enough time, though, for selection to work in this way? Some researchers argue there wasn't.
   3. Psychological mechanisms
      1. The evolution of psychological mechanisms means that human societies share some universal characteristics.
   4. Inbreeding avoidance
   5. Inbreeding results in offspring of lower genetic fitness.
   6. Inbreeding is rare in nonhuman primates.
   7. Humans around the world very rarely mate with close relatives.
      1. Adults are by and large not sexually attracted to people they grew up with as evidenced by, for example, kibbutz age-mates.
   8. Human language
   9. Humans are able to understand phonemes at a rapid pace.
      1. The meaning of linguistic constructions is based on both grammar and syntax.
      2. Language is a manifestation of a powerful general-purpose learning mechanism.
      3. There is likely a kind of universal human grammar that we are all born with.
      4. Although some animals can associate concepts with symbols, human language appears to be a derived trait.
3. Evolution and Human Culture
   1. Culture is, broadly, information that humans acquire in a myriad of ways, including through imitation, teaching, and learning.
   2. Culture is a derived trait in humans.
   3. Nongenetic transmission of culture
   4. social facilitation
   5. observational learning
   6. Culture is an adaptation.
   7. Culture allows humans to exploit various environments.
      1. Cumulative cultural adaptation gives humans more accurate information about an area than genetics alone can provide.
      2. The interplay between biology and culture is important and complex.
      3. Some aspects of culture might be maladaptive.
      4. Memes are culturally transmitted beliefs and values.
      5. The fact that culture can lead to outcomes not predicted by evolutionary biology does not mean that human behavior has transcended biology nor that evolutionary thinking is useless.