Forensic - Turning To Crime - Biology

Aim: To take a multi-factorial approach to understanding anti-social and aggressive behaviour in children with a biological focus

Method: A review article. Review and summarise findings from a selection of articles covering neuropsychological, neurological and brain imagery studies and report the findings as they relate to anti-social behaviour through child's development

Key results: Low resting heart rate, good predictor of individuals who seek excitement to raise arousal levels, creating fearless temperament. Adolescent brain still forming final connections in pre-frontal lobes until early 20's. Activity in pre-frontal lobes shown to be lower in impulsive individuals likely to be anti-social and aggressive. Offending peaks during adolescence. Birth complications and poor parenting with physical abuse and malnutrition, smoking and drinking during pregnancy all add to risk

Conclusions: Early intervention and prevention may be one effective way of reversing biological deficits that predispose to anti-social and aggressive behaviour

PHYSIOLOGICAL/INDIVIDUAL DIFFERENCES/DEVELOPMENTAL

Evaluation Points: 

• determinism vs. free will
• nature vs. nurture
• psychology as a science 
• individual vs. situational

Method issues:

• replicated from previous studies, know it is reliable
• review article from other research, reliable
• extraneous variables may arise

Scientific and grounded hard science. provides substantial evidence for nature. 

Reductionist - reaction between chemical and neurons, ignores interaction of other elements. Cannot explain how body and mind interact. 

Aim: to explain the behaviour of a large family where the males are affected by a syndrome of borderline mental retardation and abnormal violent behaviour; impulsive aggression, arson, attempted ****, and exhibitionism. 

Sample: 5 affected males from same Deutsch family

Method: Case study - data were collected from analysis of urine samples over 24hr period 

Key Results: tests show disturbed monoamine metabolism associated with deficit of enzyme monoamine oxidase A (MAOA). In each of the 5 males, point mutation was identified in the X chromosome of the gene responsible for production of MAOA

Conclusions: MAOA is involved in seretoin metabolism. Deficit in gene (leading to impaired seretoin metabolism) responsible for mental retardation in family. MAOA deficiency in family associated with a recognisable behaviourable phenotype - inability to regulate aggression. Not all of the males affected by violent behaviour. 

PHYSIOLOGICAL/INDIVIDUAL DIFFERENCES

Evaluation Points:

• determinism vs. free will
• reductionism vs. holism 
• nature vs. nurture
• psychology as a science
• individual vs. situational

Method issues:

• ethnocentric - only one family
• centred on point of view, no other explanations

scientific, grounded in hard science. could be high in validity as there are scientific results.

rare, cannot generalise from family sample. reductionist - basing on one family and one gene, will not be the same for all males with this gene

Aim: to find out if homicide rates would vary as a function of local life expectancy in Chicago, a city divided in 77 long standing community areas or neighbourhoods with relatively stable boundaries and social and economic characteristics

Method: A correlational study using survey data from police records, school records and local demographic records collected by population census

Procedure: the study examined local communities in Chicago which had lower than average male life expectancies, varying from 54.3 to 77.3 years, and plotted various correlations between collected data

Key Results: life expectancy proved to be best predictor of neighbourhood-specific homicide rates. Ranged from 1.3 to 156 homicides per 100,000 people per annum. Correlation strongly negative (-0.88). Neighbourhood-specific rate of absenteeism from school was negatively correlated with life expectancy. Parents are unwilling to invest in their child's education by enforcing attendance because they are also operating on a short-time horizon

PHYSIOLOGICAL/SOCIAL/DEVELOPMENTAL

Evaluation Points: 

• longitudinal vs. snapshot
• nature vs. nurture
• individual vs. situational 

Method Issues:

• ethnocentric - only looking at Chicago 
• population census is just a snapshot at the population at that time, does not look past or before that point 
• cannot prove one variable makes a change in another

reliable second-hand data. substantial evidence for nature in the nature/nurture debate.

reductionist - only looks at life expectancy in correlation with homicide rates, does not look at other variables. simplifies complex human behaviour