The+Biological+Level+of+Analysis+-+Genetics+-+The+Brain+-+Neurotransmitters+and+Hormones


 * **__Term__** || **__Definition__** ||
 * Frontal Brain Hypothesis || The theory that a malfunctioning relationship between the frontal cortex and the limbic system may cause criminal behavior. ||



= __ An Integrative Look at Criminal Behaviour __  - The Biological Level of Analysis - =

Are some people born to be criminals? //Modern Researchers:// //__No, but biological factors can contribute to criminality.__//

Genetics
Criminality runs in families ≠ biological Other family-related factors could also be influential

Christiansen (1977)
- Twin Studies = to what extent genetics may play a role in criminal activity - Studied 3586 sets of Danish twins

- __Concordance rate__:  **35%** in MZ male  twins **13%** in DZ male  twins  **21%** in MZ female  twins **8%** in DZ female  twins

<span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">≈ some genetic factors in criminal behaviour <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">→ low concordance rate = other factors may play a more important role __ Limitation __ : - MZ twins share common environment + identical + treated more similarly than DZ twins ... contribute to different concordance rates

Hutchings and Mednick (1975) - if both __biological__ and __adoptive__ fathers had criminal records, = **36.2%** of sons also had a criminal record - if only __biological__ father had a criminal record, = **21.4%** of sons also had a criminal record - if only __adoptive__ father had a criminal record, = **11.5%** of sons also had a criminal record - if neither father had a criminal record, = **10.5%** of sons had a criminal record

Importance of : environmental factors + genetical factors <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">→ determining behaviour __Limitations__ : - children are often placed in an environment that is similar to the one from which they were adopted - some are adopted years after birth = early experience with the birth-family <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">≈ contributed to later bahviour

<span style="font-family: arial,sans-serif;">__** Limitations of Genetic Arguments for Criminal Behaviour **__ 1) The term "Criminal Behaviour" - gene for "crime" is unlikely  2) Criminal behaviour tends to change over the lifespan - peak : individuals are in their 20s - declines in most people after the age of 30 - theorists have a difficult time explaining this

<span style="font-size: 1.3em; margin: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 5px;">** The Brain **
__ Brain Research __ - interrelationship between emotions and decision making Emotions = limbic system in the brain Decision making = frontal lobe <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">→ integration <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">≈ nature of criminal behaviour

<span style="font-family: arial,helvetica,sans-serif; font-size: 15px; line-height: 22px;">Blair et al. (1999)

- brains of convicted psychopaths - PET scans = impairment of the pathways between the amygdala //(responsible for emotional responses)// and the frontal lobe



= __difficult__ for the individual to moderate his/her emotional reactions = significant effect on how the individual interacts with others - social relationships are difficult = he/she //never// appropriately develops empathy or feelings of guilt = acts __more impulsively without regard for the consequences__

- The theory that a malfunctioning relationship between the frontal cortex and the limbic system may cause criminal behavior
 * Frontal brain Hypothesis**

Research conducted on: - convicted criminals - patients with brain damage

Antonio Damasio - effect of brain trauma in children on their later development 3-month-old infant = tumour removed from his frontal cortex When he was 9 = behavioural problems in school (inattentive/socially isolated from his peers) Free times - alone in front of the television (sometimes lose control of his emotions and physically threaten others) <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">→ supports the frontal brain hypothesis by showing a relationship between brain damage and antisocial behaviour <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">But... does not explain all criminal behaviour

<span style="font-size: 20px; margin: 0px; padding-bottom: 0px; padding-left: 0px; padding-right: 0px; padding-top: 5px;">Neurotransmitters and Hormones
- best to explain the significant gender difference in crime

US Federal Bureau of Investigation (2004) - 90.1% of apprehended murderers were male <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">→ 82.1% of those were arrested for violent crime

<span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">Low levels of neurotransmitter serotonin: <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">linked to antisocial and impulsive behaviour

Men <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;"> (responsible for the vast majority of crimes committed) <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">= generally have lower <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;"> levels of serotonin

James Dabbs <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">- violent criminals have higher <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">testosterone levels than non-aggressive criminals

= Correlational studies <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">≠ cause and effect <span style="font-family: arial,sans-serif; font-size: small; line-height: 15px;">Unsure of wether these chemical imbalances are //genetic// or the //result of the environment//

(except for the most severe cases of brain damage) factors __alone__ - are not enough to cause violence → combined with cognitive and social risk factors = criminal behaviour occurs
 * __ Biological factors __**

Essay Question: To What Extent is Criminal Behavior Primarily Biologically Based?

Core
An integrative look at criminal behavior Home