Chapter 16: Evolution and Human Behavior Minds/brains are products of Natural Selection Evolutionary Psychology Human Universals Evolution of Culture Human Behavioral Ecology

Behaviors have evolved by the same principles as other physical traits. Examples: –Language acquisition –Maze Rats –Pit Bulls and Mastiffs –Guinea Pigs and Grandmothers –Ants Large Coalitions, Complex Division of Labor, Agriculture, Domestication, Slavery, Warfare, and Architecture

Evolutionary Psychology is the study of Human Nature Species Typical Behaviors Innate cognitive mechanisms for making decisions concerning specific evolutionarily stable (ES) problems and motivate actions based on these decisions. This involves: 1.Adaptations for perceiving, recognizing, and making salient appropriate inputs to determine if a ES problem exists, and assessing the costs and benifits. 2.Choosing between possible solutions (STRATEGIES) to problems using the gathered inputs and filling in the blanks when information is incomplete. 3.Attaching appropriate emotional states that motivate actions that lead to probable solutions to ES problems.

The goal of this new science of the mind is to map out all of the decision-making rules that make up human nature. Deep-Blue and Casperoff Human Nature must be universal with low tolerance for variability Shirley McLain and Sybil Theories of Evolutionary Psychology Focus is on the design features of adaptations rather then on RS –Adaptive mismatch problem

Clerical Problem Rule: If a person has a ‘D’ rating, then his/her documents must be marked with a ‘3 ’ Social contracts and the logic of detecting cheaters: The Wason Selection Task (Leda Cosmides) D F 35

Bartender’s Problem Rule: If a person is drinking a beer, then he/she must be over 21 years old ’ Drinking a beer Drinking a coke 25 years old 17 years old

Both the Abstract and Social Contract problems are logically identical (P, not Q) Significance: –We have specialized cognitive mechanisms (adaptations for making decisions) for policing social contracts: CHEATER DETECTION –If you don’t pay the cost you are not entitled to the benefit (Reciprocal Altruism and Tit-for-Tat) –The mind is modular: Functionally specific not just capacity for reasoning Abstract (clerical) problem not in the form of a social contract and we don’t turn on the cheater detection module to solve it.

Human Universals Color Terms Hopi time and 7 Words for Snow Incest Avoidance –Kabbutz –Chinese Child Brides Expressions of Emotions Social Structures Near Universals Universals: Innate Human Nature or Universal Experience

Evolution of Culture Culture is about learning –Cultural behaviors that are not innate –Acquired in a social context Is culture unique to humans? –NO –Unique to Apes? NO but rare Social facilitation vs. Observational learning –Monkey don’t ape

Adaptations for Observational Learning led to: The ability of innovations to spread through a population without having to evolve new adaptations. Individuals not having to start from scratch, they could build on the knowledge and skill of others Cultural explosion –Homo Erectus tools (choppers) were vary useful but did not change. –With Modern Humans there was something equivalent to adaptive radiation with behaviors (tools, art, subsistence practices, etc.,) New Data indicate that Observational learning has special features –Joint attention –Functional understanding of cause and effect.

Memes and Mind Parasites Dawkins’ The Extended Genotype –Meme is like Gene –Meme is the smallest unit of memory/idea Memes like Genes are replicating units and therefore follow similar patterns of replication –Some memes die and other live (Darwin’s 1 st postulate) –Some memes are better at reproducing than others because they are more useful (Darwin’s 2 nd postulate) –Jump from mind to mind (Darwin’s 3 rd postulate) Memes are units of selection and therefore can lead to maladaptive behaviors from the perspective of individuals.

Human Behavioral Ecology Humans are rational actors who act in ways to maximize their reproductive fitness –Adaptations lead to RS –Phenotypic Gambit (Black Box) Optimization vs. Maximization –Long term cost and benefits –Lack: clutch size in birds –Optimal family size (child spacing) in Chapter 19 Optimal foraging strategies –Game choice –Size of hunting parties