Jane Mendle

Development’s Tortoise and Hare: Pubertal Timing, Pubertal Tempo, and Depressive Symptoms in Boys and Girls

Although the sequence of pubertal maturation remains consistent across most individuals, the timing and tempo of development fluctuate widely. While past research has largely focused on the sequelae of pubertal timing, a faster tempo of maturation might also present special challenges to children for acclimating to new biological and social milestones. Using latent growth curve modeling, the present study investigated how pubertal tempo and pubertal timing predicted depressive symptoms over a 4-year period in a sample of children recruited from New York City area public schools. Rate of intraindividual change in parent-reported Tanner stages was used as an index of pubertal tempo, and more advanced Tanner development at an earlier chronological age was used as an index of pubertal timing. For girls (N = 138, M = 8.86 years old at Time 1), pubertal timing emerged as the most salient factor, and the tempo at which girls progressed through puberty was not significant. In boys (N = 128, M = 9.61 years old at Time 1), both timing and tempo of development were significant; notably, however, the effects of pubertal tempo were stronger than those of timing. These findings highlight the need to consider multiple sources of individual variability in pubertal development and suggest different pubertal challenges for boys and girls.

Associations Between Father Absence and Age of First Sexual Intercourse

Children raised without a biological father in the household have earlier average ages of first sexual intercourse than children raised in father-present households. Competing theoretical perspectives have attributed this either to effects of father absence on socialization and physical maturation or to nonrandom selection of children predisposed for early sexual intercourse into father-absent households. Genetically informative analyses of the children of sister dyads (N = 1,382, aged 14-21 years) support the selection hypothesis: This association seems attributable to confounded risks, most likely genetic in origin, which correlated both with likelihood of father absence and early sexual behavior. This holds implications for environmental theories of maturation and suggests that previous research may have inadvertently overestimated the role of family structure in reproductive maturation.

Family structure and age at menarche: a children-of-twins approach.

Girls who grow up in households with an unrelated adult male reach menarche earlier than peers, a finding hypothesized to be an evolutionary strategy for families under stress. The authors tested the alternative hypothesis that nonrandom selection into stepfathering due to shared environmental and/or genetic predispositions creates a spurious relation between stepfathering and early menarche. Using the unique controls for genetic and shared environmental experiences offered by the children-of-twins design, the authors found that cousins discordant for stepfathering did not differ in age of menarche. Moreover, controlling for mothers age of menarche eliminated differences in menarcheal age associated with stepfathering in unrelated girls. These findings strongly suggest selection, and not causation, accounts for the relationship between stepfathering and early menarche.

Beyond Pubertal Timing: New Directions for Studying Individual Differences in Development

Dramatic physical and emotional changes mark puberty as one of the most important transitions of the human life span. To date, the majority of psychological studies on puberty have focused on pubertal timing, or when children mature relative to their peers. Yet understanding why puberty is meaningful requires adequate attention to multiple domains of developmental variation. The current article outlines four additional aspects of puberty relevant to health and well-being: tempo, synchrony, secular trends, and perceived development.

Depression and adolescent sexual activity in romantic and nonromantic relational contexts: a genetically-informative sibling comparison.

Adolescent dating and sexual activity are consistently associated with risk for depression, yet the pathways underlying this association remain uncertain. Using data on 1,551 sibling pairs (ages 13-18) from the National Longitudinal Study of Adolescent Health, the current study utilized a sibling comparison design to assess whether adolescent dating, sexual intercourse with a romantic partner, and sexual intercourse with a nonromantic partner were associated with higher levels of depressive symptoms independent of familial factors. Results indicated that adolescent dating, in and of itself, was not associated with depressive symptoms. The association between depressive symptoms and sexual activity with a romantic partner was fully accounted for by between-family genetic and shared environmental confounds. In contrast, sexual activity with a nonromantic partner was significantly associated with both mean levels of depressive symptoms and clinically severe depression, even within sibling dyads. This relationship was greater for younger adolescents (<15 years). These results are consistent with a growing body of research demonstrating that relationship contexts may be critical moderators of the psychosocial aspects of adolescent sexual experiences.

Pubertal Timing and Adolescent Sexual Behavior in Girls

Girls who experience earlier pubertal timing relative to peers also exhibit earlier timing of sexual intercourse and more unstable sexual relationships. Although pubertal development initiates feelings of physical desire, the transition into romantic and sexual relationships involves complex biological and social processes contributing both to physical maturation and to individual interpretations of pubertal experiences. Using a sample of female sibling pairs (n = 923 pairs) from the National Longitudinal Study of Adolescent Health, the present study investigated associations among menarche and perceived pubertal timing, age of first sexual intercourse (AFI), and adolescent dating and sexual behavior using a behavioral genetic approach. Genetic factors influencing age at menarche and perceived pubertal timing predicted AFI through shared genetic pathways, whereas genetic factors related only to perceived pubertal timing predicted engagement in dating, romantic sex, and nonromantic sex in the previous 18 months. These results suggest that a girls interpretation of her pubertal timing beyond objective timing is important to consider for the timing and the contexts of romantic and reproductive behavior.

Descriptive review: Hormonal influences on risk for eating disorder symptoms during puberty and adolescence

OBJECTIVE Puberty is an important period of risk for the onset of eating pathology in adolescent females. This review focuses on changes in reproductive hormones during puberty as one specific psychopathogenic mechanism. METHOD Studies of puberty and eating disorder-related phenotypes were identified using search databases and the reference sections of previous literature. RESULTS Correlational studies of adult women and experimental studies of animals provide evidence for the effects of reproductive hormones on eating disorder symptoms. Very few studies of puberty, however, have directly measured or tested the effects of hormonal change in samples of human adolescents. Commonly used measures of pubertal development, such as menarche or self-reported pubertal status, are relatively poor indicators of individual differences in hormones. The extent to which puberty-related hormonal change accounts for elevated risk for disordered eating remains unclear. DISCUSSION Future research is necessary to elucidate the specific relations between hormonal change during puberty and risk for disordered eating. In particular, there is a need for longitudinal studies with multivariate measurement of pubertal development, including direct measures of change in reproductive hormones.

Do maladaptive behaviors exist at one or both ends of personality traits

In the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; American Psychiatric Association, 2013) personality disorder trait model, maladaptive behavior is located at one end of continuous scales. Widiger and colleagues, however, have argued that maladaptive behavior exists at both ends of trait continua. We propose that the role of evaluative variance differentiates these two perspectives and that once evaluation is isolated, maladaptive behaviors emerge at both ends of nonevaluative trait dimensions. In Study 1, we argue that evaluative variance is worthwhile to measure separately from descriptive content because it clusters items by valence regardless of content (e.g., lazy and workaholic; apathetic and anxious; gullible and paranoid; timid and hostile, etc.), which is unlikely to describe a consistent behavioral style. We isolate evaluation statistically (Study 2) and at the time of measurement (Study 3) to show that factors unrelated to valence evidence maladaptive behavior at both ends. We argue that nonevaluative factors, which display maladaptive behavior at both ends of continua, may better approximate ways in which individuals actually behave.

Why Don't Smart Teens Have Sex? A Behavioral Genetic Approach

Academic achievement and cognitive ability have been shown to predict later age at first sexual intercourse. Using a sample of 536 same-sex twin pairs who were followed longitudinally from adolescence to early adulthood, this study tested whether relations between intelligence, academic achievement, and age at first sex were due to unmeasured genetic and environmental differences between families. Twins who differed in their intelligence or their academic achievement did not differ in their age at first sex. Rather, the association between intelligence and age at first sex could be attributed entirely to unmeasured environmental differences between families, whereas the association between academic achievement and age at first sex could be attributed entirely to genetic factors.

Early Adverse Environments and Genetic Influences on Age at First Sex: Evidence for Gene Environment Interaction

Youth who experience adverse environments in early life initiate sexual activity at a younger age, on average, than those from more advantaged circumstances. Evolutionary theorists have posited that ecological stress precipitates earlier reproductive and sexual onset, but it is unclear how stressful environments interact with genetic influences on age at first sex. Using a sample of 1,244 pairs of twins and non-twin full siblings from the National Longitudinal Study of Adolescent Health, the present study tested for gene-by-environment interactions (G × E) on age at first sex (AFS). Multivariate interaction models indicated that genetic influences on AFS were suppressed among low-socioeconomic-status (SES) and ethnic-minority compared with higher SES and ethnic-majority youth. Father absence did not uniquely moderate genetic influences on AFS. These results are broadly consistent with previous findings that genetic influences are minimized among individuals whose environments are characterized by elevated risk; however, future research would benefit from samples with larger numbers of individuals at the very low end of the SES spectrum.