Test 3 Flashcards
Cohen’s d
standardized mean difference measuring effect
d = .2
small difference
d = .8
large difference
Age of sex difference in aggression
age 2-4 years
decreases for both sexes as they grow up
Males aggression
higher total aggression
higher physical aggression
Dinsdale, Reddon, and Hurd
males had greater levels of total aggression
anger does not have significant sex difference in aggression type
does not contradict aaron sell
Aaron Sell
Males aggression is linked to physical dominance
Female aggression is linked to attractiveness
Odds ratio
probability of an outcome of an event when there are 2 possible outcomes
odds ratio = 1
equal odds for men and women
odds ratio of <1
of men fighting/# of women fighting
higher odds for women
if effect of males/effect of females
odds ratio of >1
higher odds for men
if effect of males/effect of females
Martin Daly and Margo Wilson
evolutionary psychologists who investigated aggression in their book Homicide
Advantages of studying lethal aggression from evolutionary perspective
show severe and genuine conflict
creates minimal biases in detection and reporting
heavily studied because of the social cost
massive amounts of data in time, place, and history to see patterns of adaptive structuring
Daly and Wilson’s key prediction on homicide
genetic relatedness matters
Methodological challenge when testing homicide in genetically related individuals
how to address the fact that there are differences in availability/mutual access across relationship types
Daly and Wilson approaches to solve methodological challenge
calculating homicide risk by relationship using cohabitants only, and testing collaborative homicide (co-offenders)
Homicide among cohabitants
risk highest for spouses and non-relatives
Genetic relatives more likely to be co-offenders or victim-offenders?
co-offenders
consistent with inclusive fitness theory
Cohabitants and collaborative killing bias
step siblings/step parents are lumped into the “offspring” “parents” and “relatives” categories, removing step-siblings/step parents would increase the amount of killings by non-relatives.
Motivation driving homicide
trivial altercations and insults
male honor, status, and reputation are really what is at stake
Homicide trends
- people kill people of about the same age
- mass of killings occur among adults aged 15-20
- mass of homicides reflecting adults age 20-40 killing children age 0-6, with very young (<1) children most at risk
- small crest indicating young adults that prey upon elderly (eldercide)
Frequent age-related homicide dominated by family members
age of victim was young and age of family member ranged from 10-50, suggest killing of their children
AND age of victim was high, age 80-100, and age of offender was younger, 40-80, suggesting killing of older parents
Uxoricide
killing of the wife by a husband
fillicide
killing of a son/daughter over the age of 1
Theory of male sexual proprietariness
male psychology influenced by the threat of cuckoldry and problem of paternity uncertainty which produced selective pressures to control female reproduction to neutralize threats
Relationship between residency and uxoricide
men kill wives they are separated from at double the rate of wives they co-reside with which can be explained by male mate control due to extreme jealousy/coercion
Relationship between female reproductive value and uxoricide
uxoricide is highest for young wives when reproductive value is highest because men want to control their reproduction
Potential confound of female uxoricide risk and age
young women are more likely to be murdered by husbands because husbands are also young, and young men do most of the killing
evidence against confound of female uxoricide risk
risk of uxoricide is elevated with older husbands
presence of step children increase uxoricide risk
Function of male infanticide
induce earlier resumption of female estrus, force women to be ready to bear children again quicker
select for female counter-strategy of multi-male mating to confuse paternity
Polygyny vs monogamy has more infanticide?
polygyny has higher male infanticide
Increased sex ratio (more females than males) has higher infanticide?
more females has higher male infanticide
increased reproductive skew (dominant male sires a larger percentage of offspring than other males) has higher infanticide?
increased reproductive skew has higher male infanticide
especially if keep power for short time periods
larger testicles has more infanticide?
large testicles has lower male infanticide
paternity confusion
when females mate with multiple males so they are unable to be certain whose child it is
prevents male infanticide because they do not want to risk killing their own offspring
partible paternity
belief that more than one man can contribute to the conception of a fetus
more frequently found in traditional societies of lowland South America
hypothesized function for human filicide/infanticide
paternity uncertainty, inclusive fitness/genetic relatedness, managing tradeoffs between current and future reproduction, offspring sex, threat to father
paternity uncertainty/genetic relatedness
18% attributed to fact that the child was not the parent’s own
limited resources
50% were attributed to unfavorable circumstances (twins, too many children, no male support, being unwed)
STRONGEST SUPPORTED FACTOR
infant viability
19% were attributed to infants being deformed or very ill