Textbook Notes (369,144)
Canada (162,415)
Psychology (773)
PSYC 208 (36)
Paul Wehr (21)
Chapter

Ch 3 - Life History Theory.docx

9 Pages
61 Views

Department
Psychology
Course Code
PSYC 208
Professor
Paul Wehr

This preview shows pages 1,2 and half of page 3. Sign up to view the full 9 pages of the document.
Description
Life History Theory 10/1/2012 10:22:00 AM Life History Theory  Shift from mating to parenting  Paternal uncertainty: not sure that it’s their offspring  Women don’t need to overinvest in men because they do not gain more offspring from mating with more men Primate Life-Histories  Greater encephalization  longer the life-span & longer the individual portions of the life- span  Life-span o Gestation: development before birth o Infancy: early development after birth o Juvenile periods: rapid development, but not as rapid as infancy o Adulthood o Post-reproduction  Humans live past reproduction after menopause  Why do organisms die?  Why such along post-reproductive period? o When you stop being reproductive, you have to live long enough to raise your last offspring, even if it’s at 50 Fertility & Reproductive Value  Fertility: likelihood that copulation will lead to a viable pregnancy (peaks at 25)  Reproductive Value: average number of future offspring an individual can have (peaks during late teens in women) r vs. K Strategies  r = rate of increase with no resource limitations o Environment allows for rapid growth o r-strategist produces many offspring o Insects (relative to vertebrates)  Produce offspring, don’t invest in them, so most of them die  K = carrying capacity for a habitat with resources limitations o Environment usually at carrying capacity o K-strategist produces quality offspring o Vertebrates (relative to insects) Life-history Differences  r-strategist o Many offspring o Ow parental investment o High infant mortality o Short life-span o Rapid development to reproductive state o Early reproduction o Small body size o Variable population size  Catastrophic mortality  Recolonization of vacated areas  Boom  vast starvation  K-strategist o Fewer offspring o High parental investment o Low infant mortality o Long life-span o Slow development o Delayed reproduction o Large body size o Stable population size  Constant mortality rate  Consistent habitat Rodent & Plant Examples  r-strategist o Voles  Transient habitats  3 week gestation  Large litters  Early reproduction o Dandelions  Catastrophic environment  Rapid lifecycle with early intense reproduction  K-strategist o Squirrels  Forest & prairies with constant production  6 weeks gestation  Smaller litters  Develop slower  Breed year after birth o Trees  Forests near K  Invest in foliage Humans are Extreme K-strategists  Ancestral environment was at carrying capacity  Invest heavily in offspring o 9 months gestation o Lactation  Typically produce 1 child per birth  Low infant mortality rate  80 year life-span  14-16 years to reach sexual maturity o Unlike squirrels, which are r-strategists compared to humans  Starting to act like voles, expand population rapidly, then catastrophic death Attachment  Attachment: psychological adaptation connecting the infant with mother  John Bowlby: English psychoanalyst: attachment enhanced survival and social learning  Maternal deprivation in Rhesus Monkeys: o Raised in social isolation: aggression and socially incompetent (out of fear) o Unable to provide maternal care as adults  Separation Anxiety: emotional distress observed in infants when separated from primary caregiver o Appears 6-8 months: peaks at 14-18 months o Fear of strangers  Imprinting (Konrad Lorenz) o Baby ducklings imprint on first large moving objects  follow that o If mom’s too far away, we might get eaten Attachment Styles  Mary Ainsworth: The Strange Situation o Experiment  Parent and infant are introduced to the experimental rom  Parent and infant are alone. Parent does not participate while infant explores  Stranger enters, converses with parent, then approaches infant; parent leaves inconspicuously  First separation episode: stranger’s behavior directed towards infant  First reunion episode: parent greets and comforts infant, then leaves again  Second separation episode: infant is alone  Continuation of second separation episode: stranger enters  Second reunion episode: parent enters, greets infant, and picks up infant; stranger leaves inconspicuously o Secure attachment  Explore comfortably: upset when mother leaves; calms quickly when she returns o Anxious/ambivalent attachment  Explores but anxious; protests when mother leaves; difficult to console when she returns o Avoidant attachment  Explores comfortably; unconcerned when mother leaves  Should cry when alone because you’re vulnerable  Disorganized attachment (added later) o Simultaneous avoidance and contact seeking or “freezing” o Child is afraid of its caregiver  Insecure attachment can interact with genes to produce psychopathology Senescence  Simultaneous deterioration of all biological systems due to old age o Why does life end?  Selection should favor strategies that sacrifice reproduction in the far future for reproduction in the far future for reproduction in the present (e.g. testosterone) o Early reproduction = more reproduction o Mortality rate is high over long periods o Therefore, concentrate reproduction early in life! o Selection is stronger for mutations expressed in young individuals and weaker for mutations expressed later in life.  Selection for pleiotropic genes that increase reproduction early but lead to death later  Genes are beneficial if beneficial effects outweigh the negative ones  Negative effects of genes show up later on in life, the good genes are concentrated in early life  have kids early Bereavement  Acute reaction to death of someone biologically important (6-12 months) o Grief increases o Mental and physical health deteriorates o Mortality rate increases (people tend to die more)  Asymmetry in grief reactions o Life history  Men have stronger reactions to loss of spouse  Women have stronger rea
More Less
Unlock Document

Only pages 1,2 and half of page 3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit