Biological Theories of Personality (Feb. 4) PDF

**[Biological theories of personality: Feb.04]** 1. Describe natural selection, sexual selection, intrasexual selection and intersexual selection 2. General examples of distinct forms of selection 3. Define terms reproductive capacity and minimal parental investment 4. Relate sex differe...

**[Biological theories of personality: Feb.04]** 1. Describe natural selection, sexual selection, intrasexual selection and intersexual selection 2. General examples of distinct forms of selection 3. Define terms reproductive capacity and minimal parental investment 4. Relate sex differences in reproductive capacity and minimal parental investment to sex differences in mate preferences and sapiosexuality 5. Discuss criticisms of evolutionary psychology - What are the basic principles of evolutionary theory? - How have these adapted to the study of personality? - What are the criticisms of this? **Basic principles of evolutionary theory:** Originally by charles darwin. Species are motivated by two primary goals:\ 1. Survive 2\. reproduce These are called adaptation described in **two processes**. 1. **Natural selection:**\ Hostile forces enable natural selection. -Organisms adapt characteristics that enhance their ability to survive -Organisms who possess characteristics will survive and reproduce more. -Offspring passes on characteristics to the next generation. -Successive generations the survival enhancing characteristics increase frequency until they characterize most members of the species Ex: sweet, fatty & salty foods 2. **Sexual selection:** Develop characteristics to **reproduce but not necessarily survive**. Process of developing characteristics that enhance reproduction. [Two mechanisms: sexual selection occurs]\ **1. Intrasexual selection: (same sex competition)** Competition between same sex for the interest of the opposite sex. One who possesses the characteristics to win sexual interest of opposite sex are more likely to mate and pass these characteristics to next generation. Successive generations pass on the characteristics. Ex: Aerial hover display of the male bronzed cowbird Attempt to outperform one another in turns. But not a combative form. **2. Intersexual selection: (female/male choice)** Organisms of one sex desire to mate with opposite sex. This passes on the desirable characteristics to the next generation. The characteristics pass on until that sex of a specific specie are of those characteristics. Ex: plumage of the male peacock. (evolution of brightly colored feathers of male peacocks) \*\*females show attraction to brightly colored feathers of the male. Why? It shows healthier male peacocks which would pass on to the next generation **Hypotheses about sex differences:** *How has evolutionary theories adapted the study of personality?* Evolutionary theorist focus on differences among sex, reproductive capacity and parental investment. 1. Reproductive capacity of males greater than females (sperms vs. Eggs) a. 8-12 offsprings = females b. 900 offsprings = males 2. Minimal parental investment: much greater for females c. Fetus for 9 months, nourish, nurse\... d. Male engage in copulation **[Hypothesis A] *merged by sex differences:***\ preferances of females and males are different. - Males: value appearance in mate more than female - Why? Represent capacity for reproduction - Females: value resource potential - Why? Contribute to survival of offspring R**esearch by Buss et al.: *Support Hypothesis A***\ rate desirable characteristics for mate from 1-3 - No gender difference among Sociability, Neatness, Pleasing disposition, Dependability and Good health - Males valued good looks more (indicator of good reproductive capacity) - Females valued good financial prospects (indicator of survival and maintenance) \*\*study replicated in 37 countries \*\*supporting hypothesis, A **Research Wood & Eagly: *oppose to Hypothesis A*** Finding: Countries with higher equality among genders will have less emphasis on good financial prospects. Finding 2: Gender equality has no impact on good looks. Men have greater emphasis on good looks. **Hypothesis B:** Sex differences in reproductive capacity and parental difference there is a difference among sociosexuality. (willingness to engage in uncommitted sex) Males have higher socisexuality than females. **Research Clark & Hatfiled: *support Hypothesis B*** - Males accept strangers' offer of having sex. Females reject this offer. - Females agreed on going on a date more than males. **Research Buss & Schmitt: *support Hypothesis B*** How many sexual partners you desire in a lifespan? (unmarried participants) Females =5 Males = 18 Finding: great difference in gender differences. \*\* replication among nations (females =2.5, males =13) **Research Penke & Asendorpf:** Completed a sociosexuality scale. Men scores \> Women scores Sample size effect of d=0.57 (moderate -- large difference between female & males) There were 3 facets measured: 1. Desire = 0.86 (large sex difference) 2. Attitude = 0.45 3. Behavior = 0.00 (no sex difference) **Criticisms of evolutionary psychology:** 1. Unfalsifiable: cannot travel back in time to the hypothesis 2. Controversial: parenting requires remarkable investment in which non-biological parents are unable to invest equally as biological parents **Cinderella effect:** homicide of children 0-2 years old with stepparents is greater than biological parents. (not true as we have many loving stepparents) **Heteronormative & Heterosexis**t factors are not considered in evolutionary psychology.