Multilevel meta-analysis of single-subject experimental designs: A simulation study

One way to combine data from single-subject experimental design studies is by performing a multilevel meta-analysis, with unstandardized or standardized regression coefficients as the effect size metrics. This study evaluates the performance of this approach. The results indicate that a multilevel meta-analysis of unstandardized effect sizes results in good estimates of the effect. The multilevel meta-analysis of standardized effect sizes, on the other hand, is suitable only when the number of measurement occasions for each subject is 20 or more. The effect of the treatment on the intercept is estimated with enough power when the studies are homogeneous or when the number of studies is large; the power of the effect on the slope is estimated with enough power only when the number of studies and the number of measurement occasions are large.     

MAOA and male antisocial behavior: A review

Of all the risk factors for the development of antisocial behavior, “maleness” is by far the most robust predictor. Among the numerous biological factors that have been identified as increasing risk for antisocial behavior, one of the most well-supported has inexplicably received very little attention with regard to implications for explaining why maleness is such a robust predictor. That factor is the low activity form of the monoamine oxidase-A gene. A major reason for this inattention to the MAOA-L gene appears to be the failure to appreciate that its location on the X chromosome reflects the enormous biological disadvantage of the male compared to the female. This article, after presenting a brief overview of the research which establishes that MAOA-L is one of the most well-supported biological risk factors for antisocial behaviors, explained how the enormous male biological disadvantage related to the sex difference in the prevalence of MAOA-L and thus helped explain why maleness is the most robust predictor of antisocial behavior.     

Empathy: A factor in antisocial behavior

Empathy has been accepted as a crucial factor in the development of prosocial thought and behavior. This study attempted to clarify the role of empathy in the development of antisocial and aggressive delinquent behavior. The subjects were 331 delinquents and 64 nondelinquent controls ages 12 to 18. The delinquents were found to be significantly delayed or arrested in the development of empathy. The nondelinquent group exhibited a significant age-related increase in empathy during the adolescent period, whereas the delinquent group did not. Of three delinquent subgroups utilized, the neurotics were least empathic, the psychopathics next, and the subculturals the most empathic; the groups differed significantly from each other. Aggressive delinquents were significantly lower in empathy level than nonaggressive delinquents, though differentiation by type of aggression (person or property) was not significant.This research was based on the author's doctoral dissertation. The author wishes to express his appreciation to Dr. Henry R. Angelino, Dr. Charles Wenar, and Dr. John Gibbs of the Ohio State University for their support and guidance.     

Social antecedents of children's eyewtness testimony a single-subject experimental analysis

In a laboratory simulation, a single-subject design was used to examine the effects of two types of social influence on children's eyewitness testimony, which has not been the subject of systematic behavioral analyses. This study replicates and extends findings from group-comparison studies, and shows that a topic of pressing social importance is amenable to analysis at the individual level, and therefore, potentially, to a behavioral analysis.     

A gender-linked exploratory factor analysis of antisocial behavior in young adolescents

One hundred sixty-three young adolescents (72 males, 91 females) were administered a 23-item self-report inventory measuring antisocial behaviors. Results were analyzed separately for males and females. Exploratory factor analysis showed antisocial behavior to be multidimensional and to have different factor structures for males and females. The three factors accounting for more than two-thirds of the variance in antisocial behavior are discussed in terms of specialization in drug/alcohol use and violence.     

Men,shame and antisocial behavior: A psychodynamic perspective

This paper discusses the psychosocial factors that contribute to male antisocial behavior. The role of shame and related affects is emphasized. Compensatory defenses associated with these affects are also described. Developmental concepts are reviewed in the light of recent research. Finally, some of the issues involved in doing psychotherapy with this population are discussed, with an emphasis on the value of group therapy.Parts of this paper were presented at the second annual conference onCulture, Race and Ethnicity in Group and Family Therapy which was sponsored by the Eastern Group Psychotherapy Society and New York University and was held in New York City, March 20–22, 1987.     

Personality and antisocial behaviour: A long-term study

The relationship between the personality components of psychoticism, extraversion and neuroticism, and levels of conduct disorder, delinquency and therapy responsiveness in children is investigated. A series of studies reporting short- and long-term results test Eysenck's (1970) argument that extraverts, because of their lower levels of conditionability, should feature more prominently in groups showing higher levels of conduct disorder or delinquency. The extension of that argument to include the role of psychoticism (Eysenck H.J. and Eysenck S.B.G., Psychoticism as a Dimension of Personality, Hodder & Stoughton, London, 1976) is also subjected to experimental test. Two alternative conceptions of the part played by neuroticism, either that it acts as an amplifying device (high N) or as a filter against pressure to change (low N), are considered. The results support the importance of including personality factors in the study of antisocial behaviour in children.     

Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study

Genetic and environmental influences on childhood antisocial and aggressive behavior (ASB) during childhood were examined in 9- to 10-year-old twins, using a multi-informant approach. The sample (605 families of twins or triplets) was socioeconomically and ethnically diverse, representative of the culturally diverse urban population in Southern California. Measures of ASB included symptom counts for conduct disorder, ratings of aggression, delinquency, and psychopathic traits obtained through child self-reports, teacher, and caregiver ratings. Multivariate analysis revealed a common ASB factor across informants that was strongly heritable (heritability was .96), highlighting the importance of a broad, general measure obtained from multiple sources as a plausible construct for future investigations of specific genetic mechanisms in ASB. The best fitting multivariate model required informant-specific genetic, environmental, and rater effects for variation in observed ASB measures. The results suggest that parents, children, and teachers have only a partly "shared view" and that the additional factors that influence the "rater-specific" view of the child's antisocial behavior vary for different informants. This is the first study to demonstrate strong heritable effects on ASB in ethnically and economically diverse samples.     

Male life-course persistent antisocial behavior: A review of neurodevelopmental factors

Life-course-persistent antisocial behavior, which is almost exclusively male, is arguably the single most important child clinical problem. The neurodevelopmental factors which contribute to this markedly male predominance stem from the greater male vulnerability to inherited and acquired neurodevelopmental impairments which increase the risk for antisocial behavior. The factors that contribute to this greater male vulnerability are discussed, and implications for prevention are presented.     

The heritability of antisocial behavior: A meta-analysis of twin and adoption studies

In this paper, we describe a quantitative summary of 12 twin (n=3795 twin pairs and 3 adoption studies=338 adoptees) published since 1975 which provided 21 estimates of the heritability of antisocial behavior. Medium to large effect sizes were found for genetic influences across studies, with approximately 50% of the variance in measures of antisocial behavior attributable to genetic effects. Although effect sizes did not vary across different definitions of antisocial behavior (criminality, aggression, or antisocial personality), significantly larger estimates of genetic effect were found for severe manifestations of antisocial behavior. The importance of severity was further underscored by the significantly larger effects obtained in studies using clinic-referred samples compared to the effects obtained in studies using volunteer samples. Demographic characteristics of the samples did not influence effect sizes, although studies using more stringent methodology tended to find larger effects. These results must be interpreted in light of the small literature that was suitable for the meta-analysis due to numerous methodological limitations in existing studies.     

A developmental-genetic analysis of aggressive behavior in mice: I. Behavioral outcomes

In order to investigate the proposal that modifications in developmental rate may mediate differences in aggressive behavior, two series of selective breeding studies were completed. Stable lines of mice that differed in the frequency and latency of attacks were rapidly established in two series (by S1 in the first series and S3 or S4 in the second series). For evaluation of the developmental-genetic proposal, an analysis was made of the ontogeny of aggressive expression in male mice of the two series, with a detailed report provided of the S1 and S4 generations of the second breeding series. Comparisons between the results of a longitudinal design and the results of a new type of cross-sectional design (involving only siblings, or co-sibial) indicated (a) a reliable developmental course of attack expression, with a sharp rise in early maturity and a slow decline thereafter; (b) a convergence in later maturity of the behavior of lines selectively bred for high or low aggressive behavior, if the animals had been assigned to the longitudinal design; (c) a strong effect of repeated testing on attack latency and frequency, even though the dyadic tests were brief in duration and separated by long intervals. In addition, cross-generational comparisons suggested that the selective breeding differences came about primarily by changes in the behavior of the low aggressive lines, in that these animals failed to show in early maturity the sharp increases in attack occurrence that were observed in earlier generations. Certain implications of these findings for developmental and evolutionary concepts (e.g., neoteny, acceleration, heterochrony) are discussed.     

Behavioral techniques in the treatment of obesity: A comparative analysis

The relative efficacy of the major techniques typically used in behavioral treatment programs for weight reduction was investigated using obese adult volunteers. Study 1 compared the effects of self-monitoring, self-control procedures, monetary rewards, aversive imagery and relaxation training. These procedures resulted in significantly greater weight reduction than either a no treatment group or subjects who graphed and recorded daily weight. Self-monitoring of daily caloric intake was as effective as the other methods, both singly and combined, over a 4 week treatment period. Study 2 compared the long-term effects of self-monitoring vs the full complement of behavioral techniques used in Study 1. The full behavior management program was significantly more effective, both during the treatment period and at 3 and 12 week follow-ups, although self-monitoring again produced substantial weight loss.     

A meta‐analysis of serotonin metabolite 5‐HIAA and antisocial behavior

During the past 25 years, researchers have examined the relationship between neurochemical variables and antisocial behavior in human adults, but none has been studied more intensely than the serotonin metabolite 5‐hydroxyindoleacetic acid (5‐HIAA). The goal of the current study was to employ meta‐analytic procedures to quantitatively evaluate selected evidence on the relationship between 5‐HIAA and antisocial behavior. It was expected that antisocial groups would show reduced cerebrospinal fluid 5‐HIAA compared with non–antisocial groups. This study also aimed to assess moderators that could influence the relationship between 5‐HIAA and antisociality. An electronic search and strict inclusion criteria identified 20 reports used in this meta‐analysis. Results showed a significant overall mean effect size (ES = –.45, P < .05) in the direction of lowered 5‐HIAA in antisocial vs. non–antisocial groups. A significant moderating effect for age indicated that groups comprised of antisocial individuals younger than 30 years exhibited larger negative effect sizes (ES = –1.37, P < .05) than groups with older subjects (ES = –.31, P < .05). There were no moderating effects for gender, target of violence, history of suicide, and alcoholism. Age effects may help explain age‐related declines in crime. The fact that effects did not differ based on other moderating variables supports models of reduced serotonin in antisocial individuals, regardless of type of crime or psychiatric problems. Aggr. Behav. 28:299–316, 2002. © 2002 Wiley‐Liss, Inc.     

An instrumented method for assessment and remediation of stuttering: A single-subject case study

A single-subject experimental design was used to investigate the feasibility of applying non-invasive laboratory instrumentation for examining speech physiology to assessment and biofeedback-based remediation of stuttering. Physiologic assessment facilitated the development of behavioral goals directed at changing respiratory and phonatory behaviors for this subject. Visual biofeedback therapy produced reduction in respiratory discontinuities and increased phonatory continuity, concomitant with reduced perceivable molar dysfluency. Methods used in this case illustrate a variety of options and problems related to clinical use of instrumentation. Results suggest that signals which represent respiratory, phonatory, and articulatory physiologic events may be clinically practical for evaluating and altering perceivable dysfluency.     

Linked lives: the intergenerational transmission of antisocial behavior

There is a strong assumption of intergenerational continuity in behavior patterns, including antisocial behavior. Using a 3-generation, prospective study design, we examine the level of behavioral continuity between Generation 2 (G2) and Generation 3 (G3), and the role of economic disadvantage and parenting behaviors as mediating links. We estimate separate models for G2 fathers and G2 mothers. Data are drawn from the Rochester Youth Development Study, a longitudinal study begun in 1988 during G2's early adolescence (n = 1,000), which has collected prospective data on G2, their parents (G1), and now their G3 children. Results show that intergenerational continuity in antisocial behavior is evident, albeit somewhat modest. Parenting styles and financial stress do play a mediating role, although their effects vary by G2's gender. In general, adolescent delinquency plays a larger role in linking the generations for G2 fathers, whereas parenting behaviors and financial stress play a larger role for G2 mothers.     

Hemispheric alpha asymmetries during an electromyographic biofeedback procedure for stuttering: A single-subject experimental design

A single-subject “double-reversal” experimental design was used to investigate the use of electromyographic (EMG) biofeedback on the dysfluent behaviors of a right-handed male stutterer. A systematic decrease in EMG amplitude accompanied a progressive approximation of increased verbal complexity resulting in increased fluent behavior. Electroencephalographic (EEG) alpha data (8–12 Hz) gathered during baseline and pre- and post- treatment sessions appeared to co-vary with changes in fluency with right hemispheric suppression associated with greater dysfluencies and left hemispheric alpha suppression with decreased dysfluencies. The results are discussed relative to stutterer's adoption of differing behavioral production strategies for fluent speech that are associated with hemispheric information processing strategies.