Testing causal models of the relationship between childhood gender atypical behaviour and parent–child relationship

An association between childhood gender atypical behaviour (GAB) and a negative parent–child relationship has been demonstrated in several studies, yet the causal relationship of this association is not fully understood. In the present study, different models of causation between childhood GAB and parent–child relationships were tested. Direction of causation modelling was applied to twin data from a population‐based sample (n= 2,565) of Finnish 33‐ to 43‐year‐old twins. Participants completed retrospective self‐report questionnaires. Five different models of causation were then fitted to the data: GAB → parent–child relationship, parent–child relationship → GAB, reciprocal causation, a bivariate genetic model, and a model assuming no correlation. It was found that a model in which GAB and quality of mother–child, and father–child relationship reciprocally affect each other best fitted the data. The findings are discussed in light of how we should understand, including causality, the association between GAB and parent–child relationship.     

Retrospective reports of parental physical affection and parenting style: a study of Finnish twins

Individual differences in parenting behaviors are due, in part, to genetic factors. In the present study, the authors sought to determine whether the degree of genetic influence varied according to the type of parental behavior under consideration. A population-based sample of 2,334 pairs of Finnish twins provided ratings on the physical affection, control, abusiveness, and indifference shown by their father and mother during childhood. Genetic influences, shared environmental influences, and nonshared environmental influences accounted for a small-to-medium proportion (17%-30%), a small-to-large proportion (22%-44%), and a medium-to-large proportion (37%-55%) of the variance in each parenting measure, respectively. There were no significant differences in effect sizes for mothers and fathers or across the 4 types of parental behavior. The genetic results may reflect characteristic styles with which parents respond to genetically influenced behaviors of individuals (gene-environment correlations) or individual perceptions of this relationship (gene-person correlation processes). The findings have implications for intervention and prevention work with families and for interpretation of evidence for interactions between genes and parenting behaviors.     

Validity of a test of children's suggestibility for predicting responses to two interview situations differing in their degree of suggestiveness

In the present study the relative contributions of internal and external sources of variation in children's suggestibility in interrogative situations were examined. One hundred and eleven children (48 4- to 5-year-olds and 63 7- to 8-year-olds) were administered a suggestibility test (BTSS) and the most suggestible (N=36) and the least suggestible (N=36) children were randomly assigned to either an interview condition containing several suggestive techniques or to one containing only suggestive questions. The effects of internal sources of variation in suggestibility were compared with the effects of the interview styles on the children's answers. The former did influence the children, but the external sources of variation in suggestibility had a stronger impact. Influences of cognitive, developmental factors could be found, but not when abuse-related questions were asked and high pressured interview methods were used. These findings indicate that individual assessment of suggestibility can be of some assistance when interviewing children, but diminishing suggestive influences in interrogations must be given priority.     

Effects of early exposure to mating on adult sexual behavior in male mice varying in their genetic disposition for aggressive behavior

This study examined whether the sexual behavior of adult male mice is influenced by exposure in early postnatal life to brief episodes of mating. Another focus of interest was the interplay between a genetic disposition for aggressive behavior and the early exposure experiences. The subjects used in the study were male mice of the fiftysixth generation of selection for high (Turku aggressive, TA) and low (Turku non-aggressive, TNA) levels of aggressiveness. Moderately aggressive males of the parental strain (normal, N) were also used. Subjects of each strain were exposed from 21 to 32 days of age to mating mice behind a wire mesh screen. Control subjects were placed in a comparable enclosure, but were exposed to nothing. The results showed that male mice exposed to mating early in life showed a higher rate of activities in the sexuality tests, including aggressive responses. A genetic potential for aggressive behavior was related to a higher degree of sexual activity, and the early exposures optimized the hereditary attributes. The relation between sexual and aggressive behavior is discussed. © 1994 Wiley-Liss, Inc.     

Behavioural linking of stranger rapes

A sample of serial stranger rape cases ( n = 43) that had occurred in Finland during the years 1983–2001 were studied with the objectives being to: (a) describe the characteristics of the offenders; (b) explore the structure of serial rape; and (c) demonstrate behavioural linkage through an analysis of the offenders' crime scene behaviour using both multidimensional scaling (MDS) and discriminant function analysis (DFA). The material was content analysed with regard to the occurrence of a number of dichotomous variables. The inter‐relationships of the variables was studied using MDS. The analysis revealed two previously identified major modes of interaction with the victim: involvement and hostility. Employing MDS and DFA, it was shown that the offences of different offenders were distinguishable in terms of variation between the offences of different offenders and consistency within the offences of a single offender. Using DFA, the classification accuracy clearly exceeds that expected by chance, and 25.6% of the cases were classified without any error. The results are discussed in relation to their practical utility and previous studies. Copyright © 2005 John Wiley & Sons, Ltd.     

Gender-specific social experiences and the development of aggressive and sexual behavior in male mice

This study examined influences of gender-specific social experiences on the development of aggressive and sexual behavior in male mice. To determine the effects of gender-specific social experience three different types of groups were constituted after the animals had been weaned. The subjects were randomly assigned to different treatments. Female groups were composed of one experimental male and three female cohabitants. Male groups were composed of five experimental males each, and the mixed-sex groups were composed of two experimental males and of two females. The experimental subjects stayed in these groups until the age of approximately three months, when the testing for sexual and aggressive behavior commenced. For the sexuality tests, a receptive female was placed in the home cage of the experimental male for ten minutes. A nonaggressive male was placed in the home cage of the experimental male for seven minutes for the aggression tests. The experimental males were administered both sexuality and aggression tests, the sequence of testing sexual and aggressive behavior was systematically varied in order to control the influence of the two different types of behavioral tests. The results showed that males with only male social experiences showed fewer responses and were less active in both the aggression and sexuality tests than the males from the two other types of groups. Significant positive correlations between activity during aggression and sexual tests were obtained for all three groups. © 1994 Wiley-Liss, Inc.     

Effects of early exposure to intermale aggression on the aggressiveness of adult male mice varying in their genetic disposition for aggressive behavior

This study examined whether adult male aggression is influenced by either visual or olfactory exposure in early postnatal life to brief episodes of aggression. Another focus of interest was the interplay between a genetic disposition for aggressive behavior and early exposure experiences. The subjects used in the study were male mice of the 49th generation of selection for high (Turku Aggressive, TA) and low (Turku Non-Aggressive, TNA) levels of aggressiveness. Moderately aggressive males of the parental strain (Normal, N) were also used. Subjects of each strain were exposed from 21 to 32 days of age to fighting males either behind a wire mesh or glass screen. Control subjects were isolated during the entire experimental period. At 90–100 days of age, each subjects was tested three times for its aggressiveness. Exposure to fighting males behind a wire mesh screen enhanced later aggressiveness of juvenile male mice. Juveniles exposed solely to visual cues were comparable to isolates, both groups showing less adult aggression. Early experience and the genetic disposition for aggression were correlated; TA males showing the greatest increase in aggressive behavior. The role of early olfactory learning is discussed. © 1993 Wiley-Liss, Inc.     

Differences between two strains of mice,selectively bred for high and low aggressiveness,in the capacity of male odors to affect aggressive behavior

The connection between a genetic disposition for aggressive behavior and the odor signal system in male mice was studied. The males belonged to two strains of mice which have been developed by selective breeding for high- (TA) and low aggressiveness (TNA). Urine from the high aggressive strain (TA), when applied to castrates, stimulated the aggressiveness of NMRI males while TA-soiled bedding suppressed their aggressiveness. In response to male odors from the low aggressive strain (TNA), the NMRI males showed quite contrasting reactions. The results provide evidences of a correlation between the hereditarily determined disposition for aggressive behavior and the odor signal system in TA- and TNA males.     

The relationship between aggressive and sexual behavior in male mice: Effects of testosterone and parachlorophenylalanine

The purpose of this study was to clarify the connection between aggressive and sexual behavior with the aid of testosterone propionate (TP) and parachlorophenylalanine (PCPA). Previous studies have indicated that aggressive and sexual behavior are positively correlated, and it has been suggested that both behaviors are related to the level of general arousal. Testosterone has documented effects on both aggressive and sexual behavior. It has been hypothesized that these effects are due to an increased level of general arousal. If this is the case, aggressive and sexual behavior could be restored by administration of drugs excitating the central nervous system, e.g., PCPA. The present study examined the effects of TP and PCPA on aggressive and sexual behavior in gonadectomized male mice. Control animals were injected with sesame seed oil or saline. The level of aggressiveness was assessed by means of dyadic tests with gonad-intact male opponents. For the sexuality tests, a receptive female was placed in the home cage of the experimental male. The results showed that male mice injected with PCPA were more aggressive than the males of the other groups, while the TP-exposed males expressed the most sexual activity. Compared to the control group, the PCPA and TP groups were more active in both the aggression and the sexuality tests. These findings lend support to the hypothesis that the earlier documented correlations between aggressive and sexual behavior could be due to both behaviors being dependent on a certain level of general activation. Aggr. Behav. 24:367–377, 1998. © 1998 Wiley-Liss, Inc.     

Parental nurturance and identification with own father and mother: the reproduction of nurturant parenting

The purpose of the present study was to investigate the impact of parental identification and role-modeling on parenting in the next generation, with a special focus on fathers. Ninety-four fathers and 130 mothers of five-year-old children completed structured, standardized questionnaires that assessed the subject's child-rearing practices, quality of marriage and perceived parental care and control exerted by their father and mother. Analysis using structural equation modeling revealed that paternal nurturance was significantly affected by received paternal care, as well as by the quality of the subjects own marriage. Maternal nurturance was affected by received maternal care and quality of marriage. It was also found that for fathers, quality of marriage was negatively affected by received paternal control, while for mothers, quality of marriage was negatively affected by received maternal control. For both fathers and mothers, received maternal care affected the quality of marriage positively. © 1998 John Wiley & Sons, Ltd.