MMPI profiles of adolescents charged with homicide

Study of adolescent violence has been impeded by failure to distinguish among the circumstances in which youth engage in violent behavior. The present study investigated MMPI profiles of 36 adolescent murderers and a control group of 18 adolescents charged with larceny. Homicide cases were subgrouped into those who committed homicide secondary to another crime (e.g., robbery or rape) and those who acted in the context of interpersonal conflict with the victim. While there were no significant differences between homicide and larceny groups, crime and conflict subgroups were significantly different on scales F, Hs, Hy, and Sc.     

Homicide by juvenile girls

We investigated offense characteristics for a national sample of 38,749 homicide arrestees identified in the FBI Supplemental Homicide Reports for 1984 and 1993. Analyses indicated little change from 1984 to 1993 in the circumstances of homicides committed by adolescent girls; however, there were consistent offense differences between girls and boys, and between girls and women. Homicides by adolescent girls were more likely than those committed by boys to involve interpersonal conflict rather than a criminal motive such as robbery. Girls were more likely than boys to use a knife rather than a firearm and their victims were more likely to be under the age of 13 years. Compared to women (18 years or older), girls were more likely to act with an accomplice and their victims were more likely to be female and between 13 and 20 years of age. Results were inconsistent with a stereotypic masculinization theory of the increase in female violence, but provide indirect support for the importance of domestic stress and relational conflict experienced by adolescent girls. Overall, this study supports the need for differentiated study of violence by juvenile girls, and for preventive interventions which target domestic and interpersonal stress.     

Courtesy stigma: the social implications of associating with a gay person

We investigated the operation of courtesy stigma with American male college students who reacted to a fictitious male student described as gay, rooming by choice with a gay male student, involuntarily assigned to room with a gay, or rooming with a male heterosexual. Among respondents who expressed strong intolerance of gays, the voluntary associate of a gay was perceived as having homosexual tendencies and as possessing the same stereotyped personality traits attributed to a gay. No such courtesy stigma was attached to the involuntary associate of a gay by these respondents. Relatively tolerant respondents engaged in no courtesy stigmatization at all. Thus, courtesy stigmatization occurred only under circumscribed conditions and appeared to depend more on the tendency of highly intolerant individuals to infer that a male student who apparently liked a gay individual was himself gay than on a motivation to maintain cognitive consistency.     

The rattling sound of rattlesnakes (Crotalus viridis) as a communicative resource for ground squirrels (Spermophilus beecheyi) and burrowing owls (Athene cunicularia)

Animal communication involves very dynamic processes that can generate new uses and functions for established communicative activities. In this article, the authors describe how an aposematic signal, the rattling sound of rattlesnakes (Crotalus viridis), has been exploited by 2 ecological associates of rattlesnakes: (a) California ground squirrels (Spermophilus beecheyi) use incidental acoustic cues in rattling sounds to assess the danger posed by the rattling snake, and (b) burrowing owls (Athene cunicularia) defend themselves against mammalian predators by mimicking the sound of rattling. The remarkable similarity between the burrowing owl's defensive hiss and the rattlesnake's rattling reflects both exaptation and adaptation. Such exploitation of the rattling sound has favored alternations in both the structure and the deployment of rattling by rattlesnakes.     

Psychopathy screening of incarcerated juveniles: a comparison of measures

How well do brief screening measures correspond with a full-scale assessment of psychopathy among juvenile offenders? This study compared 3 independent screening measures (the Antisocial Process Screening Device [APSD] Self-Report [A. A. Caputo, P. J. Frick, & S. L. Brodsky, 1999], the APSD Staff Rating [P. J. Frick & R. D. Hare, 2001], and the Psychopathy Content Scale [D. C. Murrie & D. G. Cornell, 2000] on the Millon Adolescent Clinical Inventory [T. Millon, 1993]) with the Psychopathy Checklist: Youth Version (PCL:YV; A. E. Forth, D. S. Kosson, & R. D. Hare, in press) in a sample of 117 incarcerated male juveniles. Modest correlations (.30-.49) were found between PCL:YV scores and those of the 3 screening measures, and there was moderate accuracy (67%-82%) in identifying youth who scored relatively high (> or = 25) on the PCL:YV. Although these results support the construct of adolescent psychopathy, they indicate substantial limitations in the use of psychopathy screening measures with juvenile offenders.     

Psychopathy scores predict adolescent inpatient aggression

This prospective study found that psychopathy scores predicted aggressive behavior among 72 adolescent psychiatric inpatients, even after controlling for age, sex, socioeconomic status, length of hospital stay, and independent self-report measures of impulsivity and conduct problems. Psychopathy was assessed within 3 days of hospital admission by clinical raters trained in the use of Hare's Psychopathy Checklist-Revised. Aggressive behavior was recorded by clinical staff members who were unaware of psychopathy ratings. Adolescents rated higher in psychopathy exhibited higher frequencies of both reactive and instrumental aggressive behavior than adolescents rated lower in psychopathy. Post hoc regression analyses revealed that psychopathy had incremental validity in predicting aggression beyond the contribution of clinical diagnosis or scores on the Millon Adolescent Clinical Inventory.     

CS-specific gamma,theta, and alpha EEG activity detected in stimulus generalization following induction of behavioral memory by stimulation of the nucleus basalis

Tone paired with stimulation of the nucleus basalis (NB) induces behavioral memory that is specific to the frequency of the conditioned stimulus (CS), assessed by cardiac and respiration behavior during post-training stimulus generalization testing. This paper focuses on CS-specific spectral and temporal features of conditioned EEG activation. Adult male Sprague-Dawley rats, chronically implanted with a stimulating electrode in the NB and a recording electrode in the ipsilateral auditory cortex, received either tone (6kHz, 70dB, 2s) paired with co-terminating stimulation of the nucleus basalis (0.2s, 100Hz, 80-105 microA, ITI approximately 45s) or unpaired presentation of the stimuli (approximately 200 trials/day for approximately 14 days). CS-specificity was tested 24h post-training by presenting test tones to obtain generalization gradients for the EEG, heart rate, and respiration. Behavioral memory was evident in cardiac and respiratory responses that were maximal to the CS frequency of 6kHz. FFT analyses of tone-elicited changes of power in the delta, theta, alpha, beta1, beta2, and gamma bands in the paired group revealed that conditioned EEG activation (shift from lower to higher frequencies) was differentially spectrally and temporally specific: theta, and alpha to a lesser extent, decreased selectively to 6kHz during and for several seconds following tone presentation while gamma power increased transiently during and after 6kHz. Delta exhibited no CS-specificity and the beta bands showed transient specificity only after several seconds. The unpaired group exhibited neither CS-specific behavioral nor EEG effects. Thus, stimulus generalization tests reveal that conditioned EEG activation is not unitary but rather reflects CS-specificity, with band-selective markers for specific, associative neural processes in learning and memory.     

Effects of validity screening items on adolescent survey data

In 2 studies, we examined the use of validity screening items in adolescent survey data. In each study, adolescent respondents were asked whether they were telling the truth and paying attention in answering survey questions. In Study 1 (N = 7,801), the prevalence rates of student risk behaviors were significantly lower after inappropriate (invalid) responders were screened out of the sample. In addition, confirmatory and multigroup factor analyses demonstrated significant differences between the factor structures of school climate scales with valid versus invalid responders. In Study 2, student perceptions of school climate were correlated with teacher perceptions in 291 schools. A bootstrap resampling procedure compared the correlations obtained with valid versus invalid responding students in each school and found that valid responders had more positive views of school conditions and produced higher correlations with teacher perceptions. These findings support the value of validity screening items in improving the quality of adolescent survey data.