Expectations regarding development during adolescence: Parental and adolescent perceptions

The aims of this study were (1) to compare the age-related expectations of parents and adolescents concerning the timing of achievement in a number of developmental tasks, (2) to examine whether personal characteristics of the adolescent affect developmental expectations, and (3) to examine whether discrepancies between the adolescents and the parents expectations are related to the amount of parent-adolescent conflict. The sample consisted of 508 families with adolescents (12–18 years old). During a home visit, a battery of questionnaires was administered individually to mothers, fathers, and adolescents. A new 24-item instrument to assess expectations for adolescents mastery of developmental tasks was developed for this study. Analyses showed that when the expectations of adolescents and those of their parents are compared at aggregate level, parents consistently indicate later ages for the achievement of developmental tasks than adolescents. Although parents have later timetables, parents and adolescents have strikingly similar views of the sequence in which achievement of developmental tasks should occur. The adolescents age appears to be the most potent predictor of developmental timetables, followed by gender, pubertal timing, and temperament, respectively. The amount of conflict within the parent-adolescent relationship was associated with differences in developmental expectations. The utility of the new instrument for research and clinical work is discussed.This research was supported by a grant from the Ministry of Health and Culture (PCOJ).     

Parent–Adolescent Conflict across Adolescence: Trajectories of Informant Discrepancies and Associations with Personality Types

Journal of Youth and Adolescence - Parent–adolescent conflict can be intense, yet parents and adolescents do not always agree on the intensity of conflict. Conflict intensity tends to change...     

Anxiety Trajectories and Identity Development in Adolescence: A Five-wave Longitudinal Study

The aim of this five-wave longitudinal study was to investigate the relationship between anxiety and adolescent identity development. Participants were 1,313 adolescents who annually completed measures of anxiety and identity. Growth Mixture Modeling (GMM) analyses demonstrated that the adolescent population was best typified by two latent growth trajectory classes: a low anxiety class (n = 1,199) characterized by a low initial level of anxiety that decreased over time and a high anxiety class (n = 114) characterized by a higher initial level of anxiety that increased over time. To answer our research question, we tested a model in which the anxiety classes predicted initial levels and rates of change of three identity dimensions: commitment, in-depth exploration, and reconsideration of commitment. Findings indicated that the high anxiety adolescents displayed a more troublesome identity development than their low anxiety peers, since their commitments became weaker with age, and they reconsidered them intensively.

Family Cohesion and Romantic and Sexual Initiation: A Three Wave Longitudinal Study

Although the relation between family relationships and the timing of sexual debut has been the focus of many studies, research on mediating factors is scarce. This study examines whether low levels of family cohesion result in an earlier onset of romantic and sexual experiences, and whether the link between family cohesion and an early sexual debut is mediated by early romantic initiation. A longitudinal sample of 314 adolescent girls and 222 boys, aged 12–17 at Wave 1, completed questionnaires at three measurement points with three year intervals. The results showed that sexual debut followed romantic initiation for 77% of the participants. For early adolescent females (aged 12–14), high levels of family cohesion resulted in a later sexual debut and this association was fully mediated by a delay of romantic initiation. Among boys and older girls, timing of romantic initiation did not mediate the link between family cohesion and timing of sexual initiation. Early adolescent girls who have negative relationships with their parents turn to romantic relationships for intimacy and support, which subsequently provide the opportunity for an early sexual debut. Low levels of family cohesion thus primarily precipitate romantic initiation and sexual initiation appears to be secondary to this process among girls in this age group.     

Characterizing the Self-System over Time in Adolescence: Internal Structure and Associations with Internalizing Symptoms

The longitudinal effects among self and identity processes, and between these processes and internalizing symptoms, are not well understood. As a result, the present study was designed to ascertain the over-time effects among identity commitment, reconsideration of commitments, and self-concept clarity, as well as to map the interplay of these self and identity processes with anxiety and depressive symptoms in early adolescence. A sample of 923 Dutch adolescents (mean age 12.4 years at Time 1; 49.3% female) participated at each of five annual assessments. Multivariate growth curve and cross-lagged panel models indicated that the association between self-concept clarity and commitment was bidirectional, that reconsideration occurs based on problems or dissatisfaction with self-concept clarity and with identity commitments, and that self-concept clarity (but not commitment or reconsideration) temporally precedes depressive and anxiety symptoms. Results are discussed in terms of the structure of the self-system and its associations with internalizing symptoms.     

The Longitudinal Role of Self-Concept Clarity and Best Friend Delinquency in Adolescent Delinquent Behavior

Journal of Youth and Adolescence - Adolescence tends to be characterized by a temporary peak in delinquent behavior, and friends in particular play a key role in the initiation and the development...     

Plasma,oral fluid and sweat wipe ecstasy concentrations in controlled and real life conditions

In a double-blind placebo controlled study on psychomotor skills important for car driving (Study 1), a 75 mg dose of +/- 3,4-methylenedioxymethamphetamine (MDMA) was administered orally to 12 healthy volunteers who were known to be recreational MDMA-users. Toxicokinetic data were gathered by analysis of blood, urine, oral fluid and sweat wipes collected during the first 5h after administration. Resultant plasma concentrations varied from 21 to 295 ng/ml, with an average peak concentration of 178 ng/ml observed between 2 and 4h after administration. MDA concentrations never exceeded 20 ng/ml. Corresponding MDMA concentrations in oral fluid, as measured with a specific LC-MS/MS method (which required only 50 microl of oral fluid), generally exceeded those in plasma and peaked at an average concentration of 1215 ng/ml. A substantial intra- and inter-subject variability was observed with this matrix, and values ranged from 50 to 6982 ng/ml MDMA. Somewhat surprisingly, even 4-5h after ingestion, the MDMA levels in sweat only averaged 25 ng/wipe. In addition to this controlled study, data were collected from 19 MDMA-users who participated in a driving simulator study (Study 2), comparing sober non-drug conditions with MDMA-only and multiple drug use conditions. In this particular study, urine samples were used for general drug screening and oral fluid was collected as an alternative to blood sampling. Analysis of oral fluid samples by LC-MS/MS revealed an average MDMA/MDEA concentration of 1121 ng/ml in the MDMA-only condition, with large inter-subject variability. This was also the case in the multiple drug condition, where generally, significantly higher concentrations of MDMA, MDEA and/or amphetamine were detected in the oral fluid samples. Urine screening revealed the presence of combinations such as MDMA, MDEA, amph, cannabis, cocaine, LSD and psilocine in the multiple-drug condition.     

An Empirical Study on the Relation Between the Critical Angle for Bullet Ricochet and the Properties of Wood

The properties of a bullet, an object, and the incidence angle determine whether the bullet will penetrate, perforate, or ricochet. In this study, the critical angle for ricochet was established for .32 Auto and 9 mm Luger bullets on Abachi, Southern Yellow Pine, Beech, and Ipe wooden boards. Results show that the critical angle differs depending on caliber and wood type. The critical angle is higher for .32 Auto bullets than for 9 mm Luger bullets and increases with increasing wood density and Janka hardness. The established critical angles for ricochet on the lightest and softest wood (Abachi) are 10.4° and 10.3° for .32 Auto and 9 mm Luger, respectively. For the heaviest and hardest wood (Ipe), the angles were 45.0° and 33.4°, respectively. The combined results on the four tested woods show a strong linear relationship between both the density and the hardness and the critical angle for both calibers.