NORMAL GENOMIC

• Gao Y, Raine A, Venables PH, Dawson ME, Mednick SA
• Reduced electrodermal fear conditioning from ages 3 to 8 years isassociated with aggressive behavior at age 8 years.
• J Child Psychol Psychiatry. 2010; 51: 550-8
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• BACKGROUND: Poor fear conditioning characterizes adult psychopathy andcriminality, but it is not known whether it is related toaggressive/antisocial behavior in early childhood. METHODS: Using adifferential, partial reinforcement conditioning paradigm, electrodermalactivity was recorded from 200 male and female children at ages 3, 4, 5,6, and 8 years. Antisocial/aggressive and hyperactive-inattentive measureswere collected at age 8. RESULTS: Poor electrodermal fear conditioningfrom ages 3 to 8 years was associated with aggressive behavior at age 8 inboth males and females. CONCLUSIONS: Results indicate that therelationship between poor fear conditioning and aggression occurs early inchildhood. Enhanced electrodermal fear conditioning may protect childrenagainst future aggressive/violent behavior. Abnormal amygdala functioning,as indirectly assessed by fear conditioning, may be one of the factorsinfluencing the development of childhood aggression.

• Costa RM, Esteves F
• Skin conductance responses to visual sexual stimuli.
• Int J Psychophysiol. 2008; 67: 64-9
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• Previous research showed that the asymmetrical direction of bilateral skinconductance responses (SCRs) remains constant regardless of task (withlarger left SCRs in men and larger right SCRs in women). However, SCRs arecontrolled ipsilaterally by structures also associated with sexualarousal, hence it could be expected that larger right SCRs arespecifically elicited by sexual stimuli. In order to test the twocompeting hypotheses, left and right SCR magnitude to three stimuluscategories (sexually explicit, sexually non-explicit and neutral) werecompared in 54 subjects (27 females). The direction of the asymmetryremained constant across stimulus types, however, unexpected sexdifferences occurred, as males had larger right SCRs and there was nolateralization in females. Interestingly, this interaction disappearedafter controlling for indicators of subjective sexual arousal, suggestingthat a specific (not previously hypothesized) processing of sexualinformation could take place.

• Skeem J, Johansson P, Andershed H, Kerr M, Louden JE
• Two subtypes of psychopathic violent offenders that parallel primary andsecondary variants.
• J Abnorm Psychol. 2007; 116: 395-409
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• Although psychopathy usually is treated as a unitary construct, a seminaltheory posits that there are 2 variants: Primary psychopathy isunderpinned by an inherited affective deficit, whereas secondarypsychopathy reflects an acquired affective disturbance. The authorsinvestigated whether psychopathy phenotypically may be disaggregated intosuch types in a sample of 367 prison inmates convicted of violent crimes.Model-based cluster analysis of the Revised Psychopathy Checklist (PCL-R;R. D. Hare, 2003) and trait anxiety scores in the psychopathic subgroup (n= 123; PCL-R > or = 29) revealed 2 clusters. Relative to primarypsychopaths, secondary psychopaths had greater trait anxiety, fewerpsychopathic traits, and comparable levels of antisocial behavior. Acrossvalidation variables, secondary psychopaths manifested more borderlinepersonality features, poorer interpersonal functioning (e.g.,irritability, withdrawal, poor assertiveness), and more symptoms of majormental disorder than primary psychopaths. When compared with thenonpsychopathic subgroup (n = 243), the 2 psychopathic variants manifesteda theoretically coherent pattern of differences. Implications foretiological research and violence prevention are discussed.

• Larsson H, Andershed H, Lichtenstein P
• A genetic factor explains most of the variation in the psychopathicpersonality.
• J Abnorm Psychol. 2006; 115: 221-30
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• The psychopathic personality can be conceptualized as three interrelateddimensions, (a) an interpersonal style of glibness, grandiosity, andmanipulation; (b) an affective disposition of callousness, lack ofempathy, and unemotionality; and (c) a behavioral/lifestyle dimension ofimpulsivity, need for stimulation, and irresponsibility, underpinning ahigher order construct, psychopathic personality. The authors used aself-report questionnaire (The Youth Psychopathic Traits Inventory) tostudy the importance of genetic and environmental influences onpsychopathic personality traits in a sample of 1,090 monozygotic anddizygotic twin pairs, aged 16-17 years. Results showed a strong geneticinfluence behind the higher order "psychopathic personality" factor,underpinned by the three psychopathic personality dimensions. Over andabove the effects to the higher order factor, significant unique geneticinfluences were also found in the callous/unemotional and in theimpulsive/irresponsible dimension, but not in the grandiose/manipulativedimension. The authors propose that this latent psychopathic personalityfactor is a meaningful target for future etiological research.

• Farrington DP
• The importance of child and adolescent psychopathy.
• J Abnorm Child Psychol. 2005; 33: 489-97
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• In commenting on the five articles in this special issue, this paperdiscusses (1) the concept of child and adolescent psychopathy, and whetheradolescent psychopaths are qualitatively distinct from other young people;(2) the measurement of adolescent psychopathy; (3) the relationshipbetween psychopathy and other personality dimensions; (4) childhood riskfactors for psychopathy; (5) psychopathy in the context of risk factorsfor delinquency; and (6) the prevention and treatment of adolescentpsychopathy. It is argued that the three dimensions of an arrogant,deceitful interpersonal style, deficient affective experience, and animpulsive or irresponsible behavioral style are most important at presentin the definition of psychopathy. An ambitious research agenda isrecommended, investigating the concept of adolescent psychopathy,developing new measures, conducting new longitudinal studies ondevelopment and risk factors, and mounting new randomized experiments onprevention and treatment.

• Raine A
• Effect of early environment on electrodermal and cognitive correlates ofschizotypy and psychopathy in criminals.
• Int J Psychophysiol. 1987; 4: 277-87
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• This study examined hypotheses concerning electrodermal hyporeactivity andpsychopathy, electrodermal hyporeactivity in schizoid antisocials, poorerscores on the Attention-Distraction factor of the WAIS in schizoidantisocials and stronger support for these relationships in those fromintact as opposed to broken home backgrounds. Thirty-seven prisoners wereassessed for psychopathy, schizotypy (anhedonia-psychoticism andschizophrenism), the WAIS, and skin conductance recorded to orienting,consonant-vowel, and 90 dB stimuli. All hypothesized relationships forpsychopathy were non-significant. High anhedonia-psychoticism scores weresignificantly associated with reduced orienting frequency (r = -0.43) andwith poor performance on Attention-Distraction (r = -0.43). Reducedorienting frequency was itself associated with poor Attention-Distraction(r = 0.61). These relationships were stronger in subjects from intact asopposed to broken home backgrounds. Conclusions are drawn with respect tothe mediating effects of attentional and social background factors inpsychophysiology-schizotypy relationships.