genetics Flashcards
behav genetics
understanding the influence of genetics on expression of characteristics and behaviours → what is inheritable? (twin and adoption studies)
molecular genetics
which genes are involved in behaviour → what genes are involved in heritable behav?
evolutionary psych?
understand how natural selection shapes psychology
determinism
-biological traits that lead to behav cannot be changed
-A person with biological determinism lacks free will and cannot be treated
*CRIMINAL BEHAVIOUR not under genetic control
phrenology
-franz gall
-Believed there was a relationship between a person’s mental attributes and the shapes and size of their skull
-Can predict behaviour and personality from physical features
-Heavily criticized, but legacy remained
atravism
-cesare lombroso
-Possession of physical features (some environmental) more common in criminals
-Known as atravism and they indicated bearer was an evolutionary throwback
-Those with them should be preemptively punished
-Seen as primitive and lesser
-Argued that biology cannot be changed
eugenics
Francis Galton
-Anything including poverty or crime was heritable due to the discussion of Darwin’s theory
-Apply reproductive control over ‘lower classes’ and the higher ups should have bigger families (positive eugenics)
-Led to WW11 genocides and sterilization of many people
-Misunderstood science..criminal behaviour cannot be fully explained using just biology
jukes family
-Late 19-early 20th century
-Sociologist Dugdale visited jails in New York
-Found blood relatives of Jukes family with half having convictions of criminal behaviour
-Attributed criminality to environment more than genetics
-Advocated for improving conditions for the poor
-Mix of environment AND genetics to fully explain criminal behaviour
twin studies (+ summary)
-Monozygotic: identical twins (MZ)
–> Split of egg but only 1 sperm, same sex
-Dizygotic: fraternal twins (DZ)
–> 2 eggs and 2 sperms
-MZ twins have a higher concordance rate for criminality → meta-analysis
-Avr 51.5% for MZ twins and 20.6% for DZ twins
-Proves there is a genetic component to criminal behav
concordance
-Degree to which pairs of people both show a particular behav or condition
-Percent that 2 twins match each other
-If 1 twin has a history of crim behav, 60% chance of the other twin having a history of criminal behaviour
problems w/ twin studies
-Sample size/sample bias
-Determination of zygosity
-Political influence/bias
-Racial bias
-Only looked at male twins
-Assumption of similar environments → possibly for MZ twins
-Homogenous populations may not be applicable elsewhere
-Ethics of those raised apart
adoption studies
-Separate genetics from environment
-heredity= biological, environment= adoptive
-Criminal convictions more common with adoptees with criminal BIOLOGICAL parent
-20% effect of heredity only while 13.5% no effects of heredity or environment
-24.5% effects of heredity and environment, 14.7% effect of environment only
-Nature + nurture
problems w/ adoption studies
-less common than twin studies
-adoption parents are screened for good environment
-Assumption of adoption immediately after birth (no relation with biological parent)
-Ethics of those raised apart
heritability studies
ROLE of genetics
molecular genetics
WHAT genes are involved + HOW MANY
MAOA gene
-MAOA-L (low-activity variant) → warrior gene because its relationship with aggression
-MAOA-H (high activity variant)
MAO enzymes
-Breaks down neurotransmitters
-Sex linked
gene x environment interactions (childhood abuse)
-Interactions of genetics and environment is a predisposition (risk factor), not a determinant
-CA + MAOA variant (low) = antisocial behav
-CA + MAOA (high) = no antisocial behav
-No CA + MAOA (low) = no antisocial behav
XYY male
-Extra Y chromosome
-0.1% in general population + 1.9% in violent criminal population
-No actual association with violence, just tall stature, acne, and slight intellectual disability
-Aggression from genetics or environment?
-Environment has a larger role on how a person turns out
Diathesis-stress model
-Diathesis: genetic vulnerability or predisposition to develop certain psychopathological condition (risk factor)
-Risky genotype + negative environment =adverse outcome
-Risky genotype + positive environ =neutral/positive outcome
Differential Susceptibility model
-Genotype plasticity
-INDIVIDUAL SUSCEPTIBILITY
-Examines susceptibility to environmental effects
epigenetics
-Processes that change gene expression, without altering genetic code
-Maternal stress during pregnancy can affect the offspring’s behaviour
-Not that researched on behaviour more researched on disease
-As environment changes, it affects the genes we express
natural selection
-Enhance reproduction and survival of species
-Process that drives adaptation
evolution of selfishness
acting in a way that increases the chance of your own survival success at the cost of someone else’s
evol of altruism
Assisting others with no benefit to oneself: behaviour may even disadvantage the altruistic
inclusive fitness
altruistic behaviour towards kin to increase odds of their own genetic success
Reciprocal cooperation
Assisting others with the expectation that they return the favour
cheating
Accepting benefits from others without reciprocating
robbery and theft
-Acquire resources to survive and reproduce
-Expropriate resource acquisition
assault and homicide
-Obtain resources
-Remove a rival
-Obtain desirable territory
-Improve social status
infanticide and siblicide
-Infanticide: if infant is unlikely to survive, no expenditure of resources
-Siblicide: Obtain resources and especially parent attention
rape + SA
-Maximize reproductive success by impregnating many females
-No expenditure of resources to raise offspring
-Females prefer higher status
child abuse
-r-strategists : large quantities of offspring with little to no parent investment (e.g. frogs)
-K-strategists: Few offspring with high parental involvement
-Killing one’s child is not conductive to reproductive fitness
-Step parents show a higher risk of killing the biological offspring
cinderella effect
-Risk of abuse is 40x higher with a biological parents and one step-parent
-Risk of death is 70x 100x likelier
-Likelihood is still VERY low (60/100,000)
interpersonal violence
-Advantages for female is physical protect for children, supply of resources, increase child survival, assistance raising offspring
-Male advantage: certainty for paternity, improve their status, increase child survival
-IPV may relate to controlling to a woman’s sexuality to deter infidelity
-Highest violence when a woman is young and fertile
-10x more likely to be abused
intrasexual competition
males engaged in competing with one another to pursue mates or resources
sex preference?
-Women prefer partners who contribute to child-rearing, prefer men with status, power, resources
-Men cater to these preferences, focus on acquiring and maintaining wealth and resources
Resistant to losing status and reputation (backing down from insults and escalation to violence)
age crime curve
-Low crime rate in childhood, when males are sexually immature and have no reason for aggression to compete for female attention
-Steep rise and peak in young adulthood, when males enter puberty and begin interasexual competition
-Decline at onset of fatherhood because costs of criminal behaviour outweighs benefits and reproductive genes are passed to the next generation
gender and crime?
-Women are less risk-adverse and may commit economic crimes out of necessity
-Women commit crimes out of NEED
-Men commit violent crimes to enhance status and power
