Shared aetiology of risky sexual behaviour and adolescent misconduct: genetic and environmental influences

Time Goes Back-Time Perspective in Polish Men with Compulsive Sexual Behavior Disorder and Risky Sexual Behavior

Many relationships between time perspective and a propensity to engage in risky behaviors or developing addictions have been demonstrated. The aim of our study was to determine the differences in intensity of individual time perspectives in people with compulsive sexual behavior disorder (CSBD) and risky sexual behavior (RSB). The analysis includes 425 men: 98 CSBD (age M = 37.99 years), 63 RSB (age M = 35.70 years), 264 without CSBD and RSB features constituting the control group (age M = 35.08 years). We used the Zimbardo Time Perspective Inventory, the Sexual Addiction Screening Test-Revised, the Risky Sexual Behavior Scale and a self-constructed survey. The comparative analysis showed a higher intensity of past-negative (p = 0.040), a lower of past-positive (p < 0.001) and a present-fatalistic (p = 0.040) outlook in the CSBD group compared to the control group. Compared to the participants with RSB, the CSBD group was characterized by a higher intensity of past-negative (p = 0.010), a lower of past-positive (p = 0.004) and a present-hedonistic perspective (p = 0.014). The RSB group also achieved higher results from the present-hedonistic perspective (p = 0.046) compared to the control group. The CSBD patients indicate a stronger tendency to focus on negative past compared to non-CSBD men, both taking and not taking RSB. The time perspective profiles of RSB men are similar to those who do not engage in RSB. The distinguishing feature of men with RSB without CSBD is a greater ability to enjoy current experiences.

Advancing the Psychometric Study of Human Life History Indicators : K Does Not Measure Life History Speed, but Theory and Evidence Suggest It Deserves Further Attention

In this article we attend to recent critiques of psychometric applications of life history (LH) theory to variance among humans and develop theory to advance the study of latent LH constructs. We then reanalyze data (n = 4,244) previously examined by Richardson et al. (Evolutionary Psychology, 15(1), 2017, https://doi.org/10.1177/1474704916666840 to determine whether (a) previously reported evidence of multidimensionality is robust to the modeling approach employed and (b) the structure of LH indicators is invariant by sex. Findings provide further evidence that a single LH dimension is implausible and that researchers should cease interpreting K-factor scores as empirical proxies for LH speed. In contrast to the original study, we detected a small inverse correlation between mating competition and Super-K that is consistent with a trade-off. Tests of measurement invariance across the sexes revealed evidence of metric invariance (i.e., equivalence of factor loadings), consistent with the theory that K is a proximate cause of its indicators; however, evidence of partial scalar invariance suggests use of scores likely introduces bias when the sexes are compared. We discuss limitations and identify approaches that researchers may use to further evaluate the validity of the K-factor and other applications of LH to human variation.

Nick Martin's Contributions to Human Sexuality Research

Genetic research into human sexuality was scarce at the end of last century. In 1992 Nick developed a 12-page questionnaire to send to twins to investigate the underpinnings of sexuality. The questionnaire included items about sexual orientation, sociosexuality and sexual behavior, and was completed by almost 5000 twins. The resulting data, unique at the time, has been used to investigate many previously unexaminable research questions. Here we describe how Nick's questionnaire contributed to our understanding of human sexuality and how we got involved in this endeavor.

Sexual Development in Adolescence: An Examination of Genetic and Environmental Influences

Sexual development entails many experiences and is a major feature of adolescence. Most relevant behavioral genetic studies, however, focus primarily on sexual behaviors associated with health risks. We took a more normative, developmental perspective by examining genetic and environmental influences on five sexual behaviors ranging from dating to pregnancy in middle (M_age  = 14.90 years) and late adolescence (M_age  = 17.85 years) in a sample of twins (N = 3,762). Overall, behaviors that are more common and socially sanctioned (e.g., dating) were more heritable than behaviors that are less common and socially acceptable (e.g., sexual intercourse). That the etiology of different sexual behaviors is tied to their normativeness highlights the importance of considering the broader developmental context when studying sexual development.

Individual- and Family-Level Determinants of Risky Sexual Behavior Among Swedish- and Foreign-Born Young Adults 18-30 Years of Age, Residing in Skåne, Sweden

In Sweden, various public health interventions have been performed to reduce risky sexual behaviors among young people and promote safer and positive approaches to sexuality, while attempting to bridge the gap between the less privileged or more vulnerable young people and their more privileged peers. This study aimed to compare the individual- and familial-level determinants of risky sexual behavior among foreign-born and Swedish-born young adults 18-30 years of age residing in Skåne, the south of Sweden. This was a cross-sectional study that used a questionnaire to collect data from 2968 randomly selected respondents between 18 and 30 years between January and March 2013. The associations were analyzed using chi-square tests, and simple and multiple logistic regression analyses. Younger age, i.e., individual-level factor, and living with only one parent or another person while growing up, i.e., familial-level factor, increased the risk of engaging in sexual risk taking for both Swedish- and foreign-born youth. Male gender was related to a higher risk of engaging in sexual risk-taking behaviors among foreign-born youth but was not as important as influence on sexual risk taking among Swedish-born youth. Parental education level, on the other hand, was significantly associated with sexual intercourse on the "first night" and early sexual debut solely among Swedish-born youth. Condom use was not associated with any family-level factor among both Swedish-born and foreign-born youth. The design of sexual reproductive health and rights messages and interventions to target risky sexual behavior among Swedish youth should take into consideration immigration status (for example, being Swedish-born or foreign-born), individual- and family-level characteristics, as well as the type of behavioral change or outcome desired.

Dimensionality and Genetic Correlates of Problem Behavior in Low-Income African American Adolescents

Researchers have long observed that problem behaviors tend to cluster together, particularly among adolescents. Epidemiological studies have suggested that this covariation is due, in part, to common genetic influences, and a number of plausible candidates have emerged as targets for investigation. To date, however, genetic association studies of these behaviors have focused mostly on unidimensional models of individual phenotypes within European American samples. Herein, we compared a series of confirmatory factor models to best characterize the structure of problem behavior (alcohol and marijuana use, sexual behavior, and disruptive behavior) within a representative community-based sample of 592 low-income African American adolescents (50.3% female), ages 13 to 18. We further explored the extent to which 3 genes previously implicated for their role in similar behavioral dimensions (CHRM2, GABRA2, and OPRM1) independently accounted for variance within factors specified in the best-fitting model. Supplementary analyses were conducted to derive comparative estimates for the predictive utility of these genes in more traditional unidimensional models. Findings provide initial evidence for a bifactor structure of problem behavior among African American adolescents and highlight novel genetic correlates of specific behavioral dimensions otherwise undetected in an orthogonal syndromal factor. Implications of this approach include increased precision in the assessment of problem behavior, with corresponding increases in the reliability and validity of identified genetic associations. As a corollary, the comparison of primary and supplementary association analyses illustrates the potential for overlooking and/or overinterpreting meaningful genetic effects when failing to adequately account for phenotypic complexity.

Nonresident fatherhood and adolescent sexual behavior: a comparison of siblings approach

Although voluminous research has linked nonresident fatherhood to riskier sexual behavior in adolescence, including earlier sexual debut, neither the causality of that link nor the mechanism accounting for it has been well-established. Using data from the National Longitudinal Survey of Youth, 1979-the Young Adult Survey (CNLSY-YA), the present study addresses both questions by comparing the sexual development of siblings discordant for age at father departure from the home and examining results across behavioral (age at first intercourse), biological (pubertal timing), and cognitive (attitudes about childbearing and marriage) sexual outcomes (N = 5,542). Findings indicate that nonresident fatherhood, beginning either at birth or during middle childhood, leads to an earlier sexual debut for girls, but not for boys, an effect likely explained by weak parental monitoring rather than an accelerated reproductive strategy.

Personality, coping, risky behavior, and mental disorders in the offspring of parents with bipolar disorder: a comprehensive psychosocial assessment

OBJECTIVES

It has been proposed that the offspring of parents with bipolar disorder (OBD), through genetic mechanisms and early family interactions, develop a heightened sensitivity to stress, maladaptive coping, and dysregulated behavior, which ultimately increases the risk for affective disorders. The current study tested certain predictions of this model by assessing different psychosocial and health-related outcomes in the OBD, including personality, coping style, smoking, suicidality, high-risk sexual behaviors, criminality, and mental health.

METHOD

The sample was composed of 74 OBD and 75 control offspring, who were between 14 and 27 years of age (mean: 19.38±3.56). Participants underwent a diagnostic interview and a structured interview to assess high-risk behavior and other maladaptive outcomes, and they completed the Revised NEO Personality Inventory and Coping in Stressful Situations questionnaire.

RESULTS

The rates of affective (31.1%) and non-affective (56.8%) disorders were elevated in the OBD compared to controls (9.5% and 32.4%). Relative to controls, OBD endorsed fewer task-oriented and more distraction coping strategies [Wilk׳s λ=.83, F(1, 136) =6.92, p<.01], and were more likely to report engaging in high-risk sexual behavior (OR=2.37; Wald=4.13, 1 df, p<05). Importantly, OBD reported elevated high-risk sexual behavior relative to controls, irrespective of affective disorder diagnosis.

CONCLUSION

The results highlight a potential risk profile for the OBD, consisting of ineffective coping strategies and risky sexual behavior and are discussed in the context of current knowledge of stress and coping in this population.

LIMITATIONS

The present findings were based on cross-sectional data and relied on offspring self-report. It would be useful to corroborate these findings with biobehavioural and longitudinal measures.

Substance use and sexual intercourse onsets in adolescence: a genetically informative discordant twin design

PURPOSE

Using a genetically informed, discordant twin analysis, the objective of this study was to examine whether earlier onset of drinking and smoking behaviors predicted early sexual intercourse onset.

METHODS

Over 3,400 adult same-sex twins from the Australian Twin Registry completed a structured interview that included retrospective reports on onsets of smoking, drinking, intoxication, and sexual intercourse and conduct disorder symptoms. A two-level frailty model estimated within-twin-pair and between-twin-pair comparisons. Onsets of smoking, drinking, drunkenness, and conduct disorder symptoms were estimated as sexual intercourse onset predictors.

RESULTS

After controlling for conduct disorder, smoking and drinking onset did not predict sexual intercourse onset for either within-twin-pair or between-twin-pair comparisons. Drunkenness onset had a significant effect on sexual intercourse onset, such that twins who first experienced alcohol intoxication at a younger age than their co-twins were also more likely to have sex earlier than their co-twins.

CONCLUSIONS

Relationships between substance use and sexual intercourse onsets may be due mostly to shared underlying factors; there was only a small relation between intoxication onset and sexual intercourse onset, and no direct relation between smoking and drinking onset and sexual intercourse onset.

Genetic influences on adolescent sexual behavior: Why genes matter for environmentally oriented researchers

There are dramatic individual differences among adolescents in how and when they become sexually active adults, and early sexual activity is frequently cited as a cause of concern for scientists, policymakers, and the general public. Understanding the causes and developmental impact of adolescent sexual activity can be furthered by considering genes as a source of individual differences. Quantitative behavioral genetics (i.e., twin and family studies) and candidate gene association studies now provide clear evidence for the genetic underpinnings of individual differences in adolescent sexual behavior and related phenotypes. Genetic influences on sexual behavior may operate through a variety of direct and indirect mechanisms, including pubertal development, testosterone levels, and dopaminergic systems. Genetic differences may be systematically associated with exposure to environments that are commonly treated as causes of sexual behavior (gene-environment correlation). Possible gene-environment correlations pose a serious challenge for interpreting the results of much behavioral research. Multivariate, genetically informed research on adolescent sexual behavior compares twins and family members as a form of quasi experiment: How do twins who differ in their sexual experiences differ in their later development? The small but growing body of genetically informed research has already challenged dominant assumptions regarding the etiology and sequelae of adolescent sexual behavior, with some studies indicating possible positive effects of teenage sexuality. Studies of Gene × Environment interaction may further elucidate the mechanisms by which genes and environments combine to shape the development of sexual behavior and its psychosocial consequences. Overall, the existence of heritable variation in adolescent sexual behavior has profound implications for environmentally oriented theory and research.

Testing putative causal associations of risk factors for early intercourse in the study of twin adults: genes and environment (STAGE)

Adverse childhood experiences and substance use have been identified as potential causal risk factors for early-onset sexual intercourse. While it is possible that exposure to these risk factors directly increases the likelihood of engaging in early intercourse, an alternative explanation is that observed associations between these variables are due to shared familial confounds. These unmeasured confounds may increase the likelihood of being exposed to these risk factors and of engaging in early intercourse. Participants drawn from a population-based study of Swedish adult twins (ages 19-47 years; N = 12,126) reported on their history of exposure to early physical and sexual trauma, cigarette use, and cannabis use. We investigated the nature of the association between these risk factors and young age at first intercourse, using a comparison of twins differentially exposed to each risk factor. When compared to non-exposed, unrelated individuals, participants who reported adverse childhood experiences or who engaged in early cigarette use or cannabis use were more likely to engage in early intercourse. However, co-twin comparisons indicated that observed associations between these risk factors and early intercourse may be due to familial factors shared within twin pairs, and risk factor exposure may not lead directly to early intercourse. Our results suggest that preventing trauma exposure or preventing or delaying adolescents' cigarette smoking or cannabis use may not effectively delay intercourse onset; instead, other aspects of the adolescent's environment should be addressed.

Why does early sexual intercourse predict subsequent maladjustment? Exploring potential familial confounds

OBJECTIVE

Previous studies have found an association between early age at first sexual intercourse and subsequent psychosocial maladjustment. Using a quasi-experimental approach, we examined the extent to which this observed association may be due to familial confounds not explored in prior research.

METHODS

Using a population-based cohort of Swedish adult twins (ages 19-47; N = 12,126), we examined the nature of the association between early sexual intercourse (i.e., first intercourse occurring before age 16) and various outcomes reflecting psychosocial health, including substance use, depression, criminal convictions, and adolescent childbearing. We used two methods--discordant-twin analyses and bivariate twin modeling--to estimate the extent to which genetic and environmental confounds explained observed associations.

RESULTS

Individuals who engaged in early intercourse were at greater risk for most of the adverse psychosocial health outcomes measured in this study. However, twin pairs discordant for engaging in early intercourse did not differ significantly in their risk for psychosocial maladjustment. Our results indicated that early age at first sexual intercourse and subsequent psychosocial maladjustment may be associated because of familial factors shared by twins.

CONCLUSIONS

Early intercourse may be associated with poor psychosocial health largely due to shared familial influences rather than through a direct causal connection. Therefore, effective and efficient interventions should address other risk factors common to early intercourse and poor psychosocial health.

Gene-environment interplay in the association between pubertal timing and delinquency in adolescent girls

Early pubertal timing places girls at elevated risk for a breadth of negative outcomes, including involvement in delinquent behavior. While previous developmental research has emphasized the unique social challenges faced by early maturing girls, this relation is complicated by genetic influences for both delinquent behavior and pubertal timing, which are seldom controlled for in existing research. The current study uses genetically informed data on 924 female-female twin and sibling pairs drawn from the National Longitudinal Study of Adolescent Health to (1) disentangle biological versus environmental mechanisms for the effects of early pubertal timing and (2) test for gene-environment interactions. Results indicate that early pubertal timing influences girls' delinquency through a complex interplay between biological risk and environmental experiences. Genes related to earlier age at menarche and higher perceived development significantly predict increased involvement in both nonviolent and violent delinquency. Moreover, after accounting for this genetic association between pubertal timing and delinquency, the impact of nonshared environmental influences on delinquency are significantly moderated by pubertal timing, such that the nonshared environment is most important among early maturing girls. This interaction effect is particularly evident for nonviolent delinquency. Overall, results suggest early maturing girls are vulnerable to an interaction between genetic and environmental risks for delinquent behavior.

Female orgasm rates are largely independent of other traits: implications for "female orgasmic disorder" and evolutionary theories of orgasm

INTRODUCTION

The criteria for "female orgasmic disorder" (FOD) assume that low rates of orgasm are dysfunctional, implying that high rates are functional. Evolutionary theories about the function of female orgasm predict correlations of orgasm rates with sexual attitudes and behavior and other fitness-related traits.

AIM

To test hypothesized evolutionary functions of the female orgasm.

METHODS

We examined such correlations in a community sample of 2,914 adult female Australian twins who reported their orgasm rates during masturbation, intercourse, and other sexual activities, and who completed demographic, personality, and sexuality questionnaires.

MAIN OUTCOME MEASURES

Orgasm rates during intercourse, other sex, and masturbation.

RESULTS

Although orgasm rates showed high variance across women and substantial heritability, they were largely phenotypically and genetically independent of other important traits. We found zero to weak phenotypic correlations between all three orgasm rates and all other 19 traits examined, including occupational status, social class, educational attainment, extraversion, neuroticism, psychoticism, impulsiveness, childhood illness, maternal pregnancy stress, marital status, political liberalism, restrictive attitudes toward sex, libido, lifetime number of sex partners, risky sexual behavior, masculinity, orientation toward uncommitted sex, age of first intercourse, and sexual fantasy. Furthermore, none of the correlations had significant genetic components.

CONCLUSION

These findings cast doubt on most current evolutionary theories about female orgasm's adaptive functions, and on the validity of FOD as a psychiatric construct.

Adolescent sexual activity and the development of delinquent behavior: the role of relationship context

Despite the well-established association between adolescent sexual activity and delinquent behavior, little research has examined the potential importance of relationship contexts in moderating this association. The current study used longitudinal, behavioral genetic data on 519 same-sex twin pairs (48.6% female) divided into two age cohorts (13-15 and 16-18 years olds) drawn from the National Longitudinal Study of Adolescent Health. Analyses tested whether adolescent sexual activity that occurred in romantic versus non-romantic relationships was associated with delinquency from adolescence to early adulthood, after controlling for genetic influences. Results indicated that, for both younger and older adolescents, common underlying genes influence both sexual behavior and delinquency. After controlling for these genetic influences, there was no within-twin pair association between sexual activity and delinquency in younger adolescents. In older adolescents, sexual activity that occurred in romantic relationships predicted lower levels of delinquency, both cross-sectionally and longitudinally, whereas sexual activity in non-romantic relationships predicted higher levels of delinquency. These results are consistent with emerging research that suggests that the psychological correlates of adolescent sexual activity may be moderated by the social context in which this activity occurs.

Cervix smear abnormalities: linking pathology data in female twins, their mothers and sisters

Mass screening for cervical cancer precursors has decreased the incidence of cervical cancer in several countries, including the Netherlands. Persistent infections of certain types of human papillomavirus are strongly associated with the development of cervical cancer. A number of factors may affect the liability to infection and subsequent progression to cervical intraepithelial neoplasia and cancer. This paper examines whether genetic factors are involved in explaining individual differences in liability. Data of 3178 women registered with the Netherlands Twin Register were successfully linked to the nationwide Dutch Pathology database that contains all results of mass screening for cervical cancer. The data from mono- and dizygotic twins and their female relatives were used to disentangle the influence of heritable and environmental factors on cervix smear abnormalities. Results showed that differences in cervix smear results clustered within families and resemblance was stronger in monozygotic twins (correlation 0.37, 95% confidence interval: 0.12-0.58) compared with other first-degree relatives (correlation 0.14, 95% confidence interval: -0.01-0.29). The familial clustering for an abnormal cervix smear is due to shared genetic factors that explain 37% of the variance in liability. The largest proportion of the variation in cervical smear abnormalities is due to unique environmental factors.

Genetic and environmental influences on risky sexual behaviour and its relationship with personality

Risky sexual behaviour is a major health issue in society, and it is therefore important to understand factors that may predispose individuals to such behaviour. Research suggests a link between risky sexual behaviour and personality, but the basis of this link remains unknown. Hans Eysenck proposed that personality is related to sexual behaviour via biological underpinnings of both. Here we test the viability of this perspective by analysing data from identical and non-identical twins (N = 4,904) who completed a questionnaire assessing sexual attitudes and behaviour as well as personality. Using genetic modelling of the twin data, we found that risky sexual behaviour was significantly positively correlated with Impulsivity (r = .27), Extraversion (r = .24), Psychoticism (r = .20), and Neuroticism (r = .09), and that in each case the correlation was due primarily to overlapping genetic influences. These findings suggest that the genetic influences that shape our personality may also predispose us to risky sexual behaviour.