Genetics and Crime Flashcards
Historian Legacy of Biological Theories of Character
Darwinian theory of natural selection first advanced in 1859.
Immediately translated into social Darwinism
Upholding rank order of society e.g. race, social class
Titanic v Lusitania
Titanic sank resulting in death of 1517 people.
Lusitania torpedoed by German U boat. death: 1198
Social Class
Titanic v Lusitania
Titanic: 1st class passengers / 2nd class secured preferential treatment for lifeboat access.
Lusitania: 1st class worst fare than 3rd class.
British passengers on Titanic died in disproportionate numbers because they queued compared to Americans elbowing.
Psuedo-Science & Eugenics
Darwinian theory of natural selection
“without any evidence, scientists concluded that human differences were hereditary and unalterable, and in doing so they precluded redemption because they imposed the additional burden of intrinsic inferiority upon despised groups. - Friedlander
Gregor Mendel
Genocide
Single genes responsible for phenotype / appearance - behaviour & morality.
e.g. Lombroso “improvidence of the savage and that of the criminal as well”
Criminal Atavism / Throwbacks
Criminals represented a reversion to a primitive or subhuman type of man characterised by physical features reminiscent of primates and early man.
Also stated criminals had less sensibility to pain, more acute sight, a lack of moral sense, including an absence of remorse, more vanity, impulsiveness, cruelty and tattooing.
Genetics to Genocide
Advances in science, medicine and welfare seen as acting counter to natural selection:
1) if natural selection was no longer able to eliminate inferiority then man would have to
2) if criminality is hereditary, then punishment would be a waste of time and effort, but elimination might be a way to eradicate crime from society - Weale 2001
Eliminating Undesirables
Strilisation:
Indiana 1899 mentally handicapped. 30 states followed.
Scandinavia
Germany
Sweden
US supreme court 1927
“It is better for all the world, if instead of waiting to execute degenerate offspring for crime, or let them starve for their imbecility, society can prevent those that are manifestly unfit from continuing their kind. The principal that sustains compulsory vaccination is broad enough to cover cutting fallopian tubes”
Nazism
Eugenics provided Hitler with ‘respectable scientific support’.
Supported by research from some of Germany’s most prestigious scientific institutions.
Sterilasation law 1933 - doctors:
- congenital feeble-mindedness
- schizophrenia
- manic depression
- epilepsy
- Huntington’s Chorea
- Blindness
- deathness
- severe deformity
- alcoholism
USA intelligence tests to diagnose feeble mindedness.
- anti-social individuals confined to asylums, custody for habitual criminals and restricted rights of gypsies.
- law for protection of German Blood
- life unworthy of life: Binding & Hoche
- 1939 mercy killings of incurables: starvation, injections, gas, experimentation.
Genocide
No understanding of mechanism by which behaviour could be inherited.
No attempt to study.
Scientific Method
Heredity v environment
Too simplistic
Need to differentiate between heredity, congenital and environmental.
Heredity and Environment
Genetics: DNA - Genes - Chromosome - Genome
Environment: all infleuences other than inheritance… environment includes prenatal events and biological events such as nutrition and illness, not just family socialisation factors. Plomin et al 2001
Interaction of genetic and environmental influences
Genetics Analysis
Molecular genetic analysis attempts to identify specific genes responsible for behaviours e.g. single gene disorders & QTL
QTL
Genetic influences on complex, common disorders are largely due to multiple genes of varying effect size that contribute additively and interchangeably.
Single gene in such a multigene system is neither necessary or sufficient for disorder.
Genetic effects involve probabilistic propensities rather than predetermined programming
Plomin 2000
Quantitative genetics
Estimates the extent to which observed differences among individuals are due to genetic differences of any sort and to environmental differences of any sort without specifying what the specific genes or environmental factors are.
Plomin 2000
Quantitative Methods
Animal breeding
Human Behaviour
- adoption
- twin
- combo
Identical Twins
MZ twins are genetically identical sharing 100% genes
Dizygygotic twins
Genetically the same as normal siblings sharing 50% of their genes.
If genetic factors are important for a trait, identical twins must be more similar than fraternal.
Non-shared environment
Variance not explained by heredity and shared family environement including measurement issues.
Family environment not shared by family members.
Environmental influences affecting development operate to make children living together no more alike than children living apart.
Outside family environment e.g. peers, schooling.
The Krays
Both contracted Diphtheria.
Reg quickly recovered but Ron remained weak.
Ron almost died from heqad injury in a fight with brother in 1942.
Believed to suffer from paranoid schizophrenia and died in Broadmoor hospital.
What is criminal?
Actus non fecit reum nisi mens sit rea
An act does not make a peron guilty unless the mind be guilty.
A criminal act need a voluntary, proscribed act by a person who acted deliberately, with intent, with knowledge that the act was illegal.
Who is criminal?
Serious offenders represent 1% population
2% males commit 70% crime
Appears to be a concentration of crime within certain individuals
Is this concentration the result of environment or genes?
Mechanism of inheritance.
Is Personality Inherited?
Animal studies
- lab mice
- domestic dogs
- Russian foxes
Human studies
- twin
- parent/child studies
Russian geneticist Dmitry Belyaeve Farm-fox experiment
- selected for low flight distance
- tame v aggressive
- physiological changes in the systems that govern body’s hormones / neurochemicals
- saw retention of juvenile traits by adult dogs, both morphological and behavioural
Plomin et al 2000
“Genetic results for personality traits assessed by self-report questionnaires are remarkably similar, suggesting that 30-50% of variance is due to genetic factors. Environmental variance is also important, but hardly any environmental variance is due to shared environmental influence” (Plomin et al, 2000)
Personality disorders
Traits that cause significant impairment or distress
PD is regarded by person as part of who they are
Long term impairments that date from childhood.
DSM-IV 10 PD’s
ASPD most researched genetically due to relevance to criminal behaviour
Personality disorders percentages
Common to community 4-11%
Offender populations
78% remand
70% in prison pop
Rates differ by offence type:
- 26% non-violent
- 50% of violent
- 33% sexual
68% sexual-violent offenders
General problems with earlier studies
sampling must be based upon complete series of Twins
Zygosity must be reliably determined
Concordance tells of genetic and shared environment
Norwegian Twin Study (Dalgard & Kringlen 1976)
Twin register of 66000 twins X referenced with criminal register yielded 205 pairs of male twins
Zygosity typing = blood & serum
49 MZ & 89 DZ
Using strict concept of crime:
41% MZ & 26% DZ concordant
Danish Twin Study (Cloninger et al, 1978)
Register 3966 twins
Criminality: police & penal registers
Zygosity: questionnaire and serum
Summary of Twin Studies
Early studies reported ery high concordance
but
- flawed - sampling, zygosity and concordance.
Later studies, more experimental control, varied concordance. But still there are potential problems with environmental assumptions.
Adoption Studies
Genetically unrelated people living together
Similarity - environment
Differences - Genetics & NSE
Genetically related people living apart
Similarity - Genetics
Differences - Environment
Findings from Danish Adoption Study (Mednick et al, 1984)
- strong genetic effect
- gene / environment interaction i.e. adoptive parents’ criminality had no effect of offspring unless biological parents were also criminal
Swedish Adoptees Criminality (Bohman et al, 1982)
862 men adopted <3 yrs old
Placement homes had to be non-criminal & non-alcoholic. No info on birth parents was given to adoptive parents.
Criminal: suspended or actual prison / heavy fine.
Petty offences: criminal biological fathers more likely to ave criminal sons.
BUT
Violent offences: alcoholic fathers more likely to have violently criminal sons. This suggests an interaction as alcohol and criminality more likely to be present in violent rather than nonviolent offences.
Summary of Adoption Studies
Evidence of genetic effect
Evidence for environment / gene interaction
No evidence for shared environmental effect
Evidence for a need to differentiate crime type
Antisocial Personality
What is criminal?
Antisocial behaviour e.g. lying, cheating, stealing.
APD - chronic indifference to & violation of the rights of others.
Psychopaths when believed to be a mental illness.
Sociopaths when assumed to be caused by social conditions.
Diagnosis more common in men.
ASP Studies
Twin studies MZ 50% and DZ 22%
Adoption study found familial resemblance mainly due to genetics.
Meta Analysis of Twin & Adoption Studies
Meta analysis: combines studies to calculate overall effect sizes.
46 twin & adoption studies of anti social behaviour
Shared environmental 24%
Genetics 40%
Non-shared environmental 36%
Warrior gene - Monoamine oxidase A aka MAO-A
Association between a rare 2R repeat and an increase in the likelihood of committing serious crime or violence has been found.
Version of gene that a person carries may determine or at least significantly influence the impact of childhood experience of violence.
Psychopathy
50-75% offenders are ADP.
15-25% psychopathic.
“self centred, callous, remorseless person profoundly lacking in empathy and the ability to form warm emotional relationships with others, a person who functions without the restraints of conscience (Hare 1993)
Famous psychopaths: John Wayne Gacy, Ted Bundy, Richard Ramirez, Ian Brady
Genetic Research: Blonigen & Colleagues 1
Twin study: 165 MZ & 106 DZ twin pairs.
Found “substantial evidence of genetic contributions to variance in the personality construct of psychopathy” - Blonigen et al, 2003.
Genetic Research: Blonigen and Colleagues 2
188 MZ & 101 DZ male twin pairs
223 MZ & 114 DZ female twin pairs
Interpersonal-affective (fearless dominance) & antisocial (impulsive antisociality) traits of psychopathy are equally and substantially heritable with each accounting for roughly half of the total variance in both men and women.
Genetic Research on Young People
3687 UK 7yr old twin pairs found that 70% of the individual differences in antisocial behaviour & callous/unemotional traits were accounted for by genes. (Viding, et al 2005)
1090 Swedish 16-17 yr old twin pairs.
“a genetic factor explains most of variation in psychopathic personality (Larrson et al).
Twins Early Development Study
Indicated that within early-onset group there are at least two etiologically distinct groups of children.
Antisocial behaviour in 7yr children with callous and unemotional traits is under strong genetic influence.
Whereas AS behaviour in children without such personality traits is primarily environmentally mediated.
Psychopathy: Genes and Environment
Genetics dictate brain function.
Psychopaths show unusual brain wave patterns on EEGs. Have low HR&CS.
Perform unusually on cognitive tests.
Environment interacts with predisposition: Good environment leads to white collar criminal / shady business.
Adverse environment leads to criminality.
Violent environmental leads to violent criminality.
M’Naughten Rule
“Capable of distinguishing between right and wrong”
If not the law accepts that he is, because of his nature, less open to its power.
Genome Project & Future Research
Human Genome Project has decoded the human genome.
Freely available for research.
Future possibilities include genetic investigation of criminal populations.
Screening? Prevention?
Ethics
“One day, we may be able to use genetic analysis to predict far in advance that someone is destined to develop a severe and dangerous personality disorder. Would such a child then be marked out for indefinite imprisonment on reaching adolescence?” (Turner, 1999)
“XYY speculation resulted in Johns Hopkins University, with financial backing from the National Institute of Mental Health, conducting XYY screening in juvenile detention facilities and in black ghettos. Plans included releasing the results to juvenile courts and correctional agencies. Testing children in public schools and day nurseries were other target areas.” (Nassi & Turner, 1976)
Dangerous and Severe Personality Disorder Programme
DSDP programme aimed at people who have committed a violent or sexual crime and have been detained under the criminal justice sysem or current mental health legislation.
Use of a twin study sample that will allow us to look at relative importance of genes and environment will lay the foundations for future molecular genetic research that can identify specific genes which will promote early screening and preventative inverventions.
