Transcultural comparisons of self-image in German and United States adolescents

Based on the Offer Selfimage Questionnaire (OSIQ), the selfimage of German and United States adolescents was compared. The German study was based on OSIQ protocols from 365 adolescents in West Berlin while the American sample comprised adolescents drawn from seven cities in the United States. With respect to three scales, United States adolescents report better adjustment than do the German adolescents. These scales were Mastery of the External World, Vocational and Educational Goals, and Superior Adjustment. In general, these two Western societies share more similarities than differences in the selfimages of their adolescents.Received M.D. and Ph.D in Psychology from the University of Hamburg, Germany. Research interests are high-risk studies, child psychiatric epidemiology, and adolescence.Received M.D. from the University of Chicago. Major interests are concepts of mental health and the developmental psychology of adolescence.Received J. D. from the University of Chicago School of Law; received Ph.D. in Human Development from the University of Chicago. Research interests are adolescence and delinquency.Received Ph.D. in Psychology from the University of Chicago. Major interests are psychotherapy research and adolescence.     

The self-image of adolescents: A study of four cultures

This paper describes the utilization of the Offer Self-Image Questionnaire (OSIQ) for research purposes on a variety of adolescent populations and demonstrates the OSIQ's effectiveness in meaningfully separating normal, juvenile delinquent, and emotionally disturbed adolescents; older and younger teenagers; males and females. It also considers the utilization of the OSIQ in four different cultures (United States, Ireland, Australia, and Israel) and concentrates on the results obtained when the OSIQ is given adolescents in these four cultures. It discusses the findings and points to some of the methodological problems which are inherent in doing cross-cultural research.Presented at the American Educational Research Association meeting in San Francisco, California, April 20, 1976.Received his M.D. from the University of Chicago. He interned at the University of Illinois and took his psychiatric residency at Michael Reese Hospital and University of Chicago. He is a graduate of the Institute for Psychoanalysis in Chicago. Major interests have been concept of mental health and the developmental psychology of adolescence.Received his Ph.D. in human development from the University of Chicago. Research interests are adolescence and delinquency.Received his Ph.D. in psychology from the University of Chicago. Major interests are psychotherapy research and adolescence.     

Construct Validity of the Offer Self-Image Questionnaire and Its Relationship with Self-Esteem,Depression, and Ego Development

Construct validity of the Offer Self-Image Questionnaire (OSIQ) was studied in a sample of 194 normal Finnish adolescents from 14 to 16 years of age. Confirmatory factor analysis provided support for the hierarchical structure of adolescents’ self-image with 5 lower-order factors loading on a single higher-order factor. Lower-order factors were Personally Anxious Self, Social Relationships, Sexual Attitudes, Family Relationships, and Social Conscience. The relationships between the self-image areas of the OSIQ, global self-esteem, depression, and ego development were also examined. The results support the construct, convergent, and discriminant validity of the presented structure of the OSIQ.He received M.A. from University of Helsinki. Major research interest concern adolescent psychological developmentHe received Ph.D. from University of Helsinki. Major research interests include psychosocial health risks and organizational behavior.He received M.D. from Lausanne University and Ph.D. from Helsinki University. Major research interests include attachment issues, fatherhood, and foster parenting.He received his Ph.D. in psychiatry from the University of Helsinki. Major research interests are developmental theory of adolescence and personality development of adolescents in chronic illness.He received Ph.D. from University of Cambridge. Major research interests concern personality and developmental psychology.     

Psychiatrists' concept of adolescent self-image

The objectives of the study were as follows: (1) to determine the accuracy of psychiatrists' concepts of the self-image of healthy and disturbed adolescents, and (2) to examine the effects of psychiatrists' gender, experience, and specialization on the accuracy of these concepts. Toward this end, eighty-four psychiatrists completed a modified Offer Self-image Questionnaire as they believed a mentally healthy 15-year-old of their gender would respond. These responses were compared to those of 140 nonpatient 15-year-olds. Sixty-one psychiatrists completed the questionnaire as they believed a disturbed 15-year-old of their gender would respond. These responses were compared to the responses of 70 psychiatric inpatient 15-year-olds of the same diagnosis. The results were that psychiatrists had a more accurate concept of normal adolescents' self-image than was found in 1981. However, their view of the self-image of disturbed adolescents was more psychopathological than the disturbed adolescents viewed themselves. Psychiatrists' gender, number of years postresidency, and type of training had no effect on the accuracy of the psychiatrists' concepts. The results demonstrate that while psychiatrists work with disturbed adolescents, they have a more accurate perception of the self-image of normal adolescents. This can effect the diagnosis and treatment of adolescent patients.Presented on May 24, 1994, at the annual meeting of the American Psychiatric Association, Philadelphia, Pennsylvania.Received M.D. from Rush Medical College. Research interest is in adolescent psychology.Received M.D. from University of Chicago. Research interests are in adolescent development psychology and psychopathology.Received Ph.D. from University of Chicago. Research interests are in psychotherapy research and adolescent psychology.Received Ph.D. in Clinical Psychology from Northwestern University. Research interests are in adolescence and child development.     

A self-image questionnaire for young adolescents (SIQYA): Reliability and validity studies

This article describes a questionnaire measure of self-image designed for young adolescents. It represents a downward extension of the Offer Self-Image Questionnaire and utilizes nine scales from that instrument: Emotional Tone, Impulse Control, Body Image, Peer Relationships, Family Relationships, Mastery and Coping, Vocational/Educational Goals, Psychopathology, and Superior Adjustment. This 98-item questionnaire elicits responses on a 6-point Likert-type scale. The alpha coefficients for each scale are high, indicating a high degree of internal consistency among the items. The validity of this instrument is examined through factor analyses and through the association of these scales with other measures of self-image. The results suggest that this questionnaire provides a useful way to assess self-image among young adolescents.This research was supported by Grant MH 30252/38142 to Anne Petersen.Received Ph.D. from the University of Chicago in 1973. Research interest is biopsychosocial development in adolescence, with a focus on sex differences.Research interests are vocational development and contextual influences on development in early adolescence.Research interests are the influences of adolescent and parent development on family relationships.Received M.D. from the University of Chicago. Research interests are the psychology and psychopathology of adolescents.Current research interests are social cognition and peer relationships during early adolescence.     

The Offer Self-Image Questionnaire for adolescents: Psychometric properties and factor structure

The reliability and validity of the Offer Self-Image Questionnaire (OSIQ) for adolescents were investigated using data from an Australian sample of male and female school students, with an average age of 14.9 years (n=216). Reliability coefficients were high for all subscales except the Morals subscale. Results indicated significant correlations of the OSIQ subscales with Lang and Tisher's Children's Depression Scale of 1978 and small correlations with a measure of social desirability. A factor analysis yielded five interpretable oblique factors that support the concept of a multidimensional self-image. Identification of items contributing little to the subscale alphas, and not loading on the factors yielded by the factor analysis, highlights the need for further development and validation of the OSIQ. Implications for the development of the self-concept at adolescence are also discussed.Received Ph.D. from University of Queensland. Research interests are adolescent development, self-concept, and career development.Received Ph.D. from University of Queensland. Research interests are adolescence, family, and communication.     

Longitudinal Association Between Parenting Practices and Early Sexual Risk Behaviors among Urban African American Adolescents: The Moderating Role of Gender

A sample of 274 African American families, living in impoverished neighborhoods with high HIV rates, participated in a longitudinal study of adolescent sexual development when children were in the 4th or 5th grade. Self-report and observational measures of parental warmth and parental behavioral control were collected from adolescents and parents at Time 1, and youth reported if they had initiated intercourse at Times 1 and 2. Regression analyses suggested that gender moderated associations between parental behavioral control and engagement in adolescent sexual behaviors. More generally, findings suggested that boys reared in low control/high warmth (i.e., permissive) homes and girls reared in high control/low warmth (i.e., authoritarian) homes were particularly at risk for early sexual behaviors. Clinical implications and directions for the future research are discussed.Doctoral Candidate in Clinical Psychology at Loyola University Chicago. Received her B.S. in Psychology and African & African American Studies from Duke University and her M.A. in Clinical Psychology from Loyola University Chicago. Her major research interests include the role of family and mental health factors in HIV risk exposure among urban African American adolescents.Professor, Department of Psychology, Loyola University Chicago. Received his Ph.D. in 1987 from Virginia Commonwealth University. His major research interests are family relations during adolescence, physical disabilities, pediatric psychology, developmental psychopathology, and statistical applications in psychologyAssociate Professor of Psychology in the Department of Psychiatry, Institute for Juvenile Research, University of Illinois, Chicago. Received her PhD in Child Psychology from the Institute of Child Development at the University of Minnesota in 1987. Her current research interests include developmental transitions during adolescence, as well as from pre-school to middle childhood, among typically developing children as well as children with special needs     

Self-Esteem Enhancing Reasons for Having Sex and The Sexual Behaviors of African American Adolescents

A sample of 146 African American adolescents living in impoverished neighborhoods with high HIV rates participated in the Chicago HIV Prevention and Adolescent Mental Health Project (CHAMP), a longitudinal study of adolescent HIV risk exposure. The current study examined self-reported reasons why African American adolescents may participate in risky sexual behavior. Adolescents completed a questionnaire regarding their sexual behaviors and reasons for having sex at Wave 3 of data collection. Findings from the study revealed that females used condoms less consistently while males had more sexual partners and sexually debuted earlier. Regression analyses also indicated that males were more likely to endorse self-esteem enhancing reasons for having sex and those who did also reported a higher number of sexual partners. Males were more likely to endorse power-related reasons for having sex and those who did tended to sexually debut earlier. Across both genders, results suggested that those adolescents who endorsed more self-esteem enhancing reasons for having sex were less likely to use condoms consistently. Implications for prevention programs and future research are discussed. Doctoral candidate in the Clinical Psychology Program at Loyola University Chicago. She received her Master of Arts from Loyola University Chicago in Clinical Psychology. Her research interests are in HIV/AIDS prevention in African American communities, particularly amongst adolescent girls. Professor of Clinical Psychology and Director of Clinical Training at Loyola University. He received his Ph.D. in Clinical Psychology from Virginia Commonwealth University. His interests lie in family relations during early and late adolescence, developmental psychopathology, the interface between developmental psychology and clinical child psychology, pediatric psychology (e.g., adolescents with physical disabilities), statistical applications in psychology, and research design. Associate Professor of Psychology in Psychiatry at the University of Illinois at Chicago. She received her Ph.D. in Child Psychology from the University of Minnesota at Minneapolis Her research interests lie in normative developmental processes during the transition to adolescence.     

From trust on intimacy: A new inventory for examining erikson's stages of psychosocial development

A new inventory for examining the first six of Erikson's psychosocial stages is described. The self-report questionnaire, developed in a pilot study of 97 adolescents and tested in a study of 622 adolescents, has 12 items for each subscale. Measures of reliability and validity are reported. It is concluded that the Erikson Psychosocial Stage Inventory (EPSI) is a useful measure for researchers interested in development from early adolescence and in mapping changes as a function of life events.This research was supported by a grant from the Education Research and Development Committee.Received Ph.D. from University of Melbourne. Current research interests are adolescent adjustment, ethnicity, and sex-role psychology.Received Ph.D. from University of Melbourne. Current research interests are effects of unemployment and adolescent adjustment.Received Ph.D. from Florida State University. Current research interests are sex-role psychology and adolescence.     

Israeli adolescents' self-image profile

Seven hundred and seventy-two Jewish Israeli male and female high school students (aged 14–18) responded to a Hebrew version of the Offer Self-Image Questionnaire (OSIQ). Results show that, much like the American adolescents, the majority of the Israeli respondents are happy and well-adjusted, although a noticeable minority experiences some personal trouble. Gender and age differences show that males hold a more positive self-image than do females, and that age differences among males are larger than among females. Comparisons with the American norm sample indicate that the Israeli and American self-image profiles differ significantly on only three scales. Israelis report a higher impluse control, and lower morals and vocational and educational goals. These results are discussed in terms of ecological and cultural explanations, and the need for extending OSIQ research to additional sectors of Israeli society is noted.Received Ph.D. from Hebrew University of Jerusalem. Research interest is adolescents' psychosocial development.Received Ph.D. from the University of Manchester, England. Major research interest is personality development in adolescents.     

Peer knowledge of and reactions to adolescent suicide

Questionnaire data were obtained from 120 high school students on their (1) knowledge of risk factors that identify potential suicidal behavior in peers, (2) attitudes toward peers who attempt or commit suicide, and (3) ability to respond appropriately to suicidal messages from peers. Overall, relatively few adolescents possessed accurate information, and many had misinformation concerning various warning signs. Furthermore, respondents expressed negative attitudes toward peers who attempt or commit suicide, and generally were unable to respond sensitively and appropriately to suicidal communications. These results have implications for suicide education programs for adolescents.This study was based on a Masters Thesis conducted by the first author under the direction of the latter two authors. Preliminary results of this investigation were presented at the Midwestern Psychological Association, Chicago, 1988.Received M.A. in clinical psychology from Loyola University. Current research interests include bulimia and alcoholism.Received Ph.D. in clinical psychology from Vanderbilt University. Primary research interests involve community psychology, prevention programs, and child psychology.Received Ph.D. from University of Chicago. Research interests include issues in adolescence and eating disorders.     

Age segregation of adolescents in and out of school

In a naturalistic study of age segregation during adolescence, 403 adolescents making up 153 separate groups were observed in three high schools and seven out-of-school settings. Age segregation was extensive, especially in school, among older adolescents in same-sex groups of friends. More mixed-age association was observed out of school among younger adolescents who were in mixed-sex groups containing relatives. Adolescents were most often observed with friends who were other adolescents, next with adults, and least frequently observed with children. Parents, particularly fathers, were rarely present. It was suggested that age segregation during adolescence is the result of a lack of contact with relatives.Received his Ph.D. from Michigan State University in 1974. Major research interest is parent-adolescent relations.Major research interests are adolescence and clinical psychology.     

The “impulsivity index”: Its application to juvenile delinquency

An objective, composite index of impulsivity, made up of three measures of reactivity to color on the Rorschach and amount of discrepancy between performance and verbal IQ on the Wechsler Scales, is proposed. It was predicted that impulsiveness as measured by this index would be associated with self-perception of impulsivity. Moreover, it was predicted that impulsiveness, whether objectively or subjectively measured, would tend to be associated with a history of greater and more frequent delinquency. The major hypotheses were confirmed. In addition, the data suggested that delinquents from higher socioeconomic levels may be more impulsive than their lower class counterparts. Additional work on refining and validating the impulsivity index is indicated.This work has been supported by Grant No. A70-15 from the Illinois Law Enforcement Commission.Currently a Ph.D. Candidate in Human Development at the University of Chicago. Major research interest is in cognitive development during adolescence.Received M.D. from the University of Chicago. Major research interests are the developmental psychology of adolescence and the etiology of juvenile delinquency.Received M.D. from Marquette University. Major research interests are in juvenile delinquency and psychotherapy of adolescents.Currently a Ph.D. Candidate in Human Development at the University of Chicago. Major research interest is in juvenile delinquency.     

Adolescent idolization of pop singers: Causes,expressions, and reliance

The study examines the phenomenon of adolescents' idolization of pop singers. Male and female adolescents from three age groups (ages 10–11, 13–14, and 16–17) were compared with regard to the intensity of idolization, its behavioral manifestations, causes for selecting the idol, and reliance for knowledge on the idol. The results of self-reports indicated that the phenomenon of idolization, expressed especially in worshipping and modeling, is strongest in the youngest age group and decreases in intensity with age. Also, it was found that girls idolize singers more than boys. The youngest age group, especially girls, rely on singers with regard to knowledge concerning personal matters. These findings were explained within the frameworks of gender differences, adolescence characteristics, and youth culture development.This paper was prepared while the first and the third authors were on sabbatical at the Department of Psychology, Maryland University, College Park, Maryland.Received Ph.D. in clinical psychology from the Hebrew University, 1974. Research interests include school psychology, social cognition, and media psychology.Received Ph.D. in Social Psychology from the University of Pittsburgh, 1974. Research interests include political psychology, social psychology, and social development.Received Ph.D. in statistics from the Hebrew University, 1976. Research interests concern applied statistics and nonparametric statistics.Received MA in clinical child psychology, Department of Psychology, Tel Aviv University.     

Perceived Support and Internalizing Symptoms in African American Adolescents: Self-Esteem and Ethnic Identity as Mediators

Existing research leaves a gap in explaining why African American adolescents do not exhibit more anxiety and depression than other youth, at the same time that they experience more contextual risk factors. The current study examined the roles of social support as well as possible mediators self-esteem and ethnic identity (sense of belonging to one’s ethnic group) in reducing internalizing symptoms in 227 African American adolescents (mean age = 12.55). Structural equation models indicated that self-esteem and ethnic identity partially mediated the relation between social support and depression. For depression, ethnic identity accounted for more of the social support effect for males, whereas self-esteem had more impact for females. The mediation model for anxiety was supported in females, with self-esteem more important than ethnic identity. The results suggest that ethnic identity and self-esteem function as important links in how social support reduces internalizing symptoms in African American youth. Assistant Professor, Clinical Psychology, Loyola University Chicago. Received Ph.D. in Psychology from The University of Memphis. Current interests include coping and resilience in African American youth and the role of family characteristics in children and adolescents’ stress and coping processes. Teaching Associate, School of Education and Social Policy, Northwestern University. Received Ph.D. in Psychology from University of Rhode Island. Research interests include ethnic identity in African American youth and the effects of exposure to violence on well-being. Assistant Professor, Human Development and Social Policy, Northwestern University. Received Ph.D. in Psychology from University of California, Riverside. Primary research examines the nature and effects of socialization, father’s involvement, and how they interact with gender, race, and SES to impact youths’ academic and social development. Professor, Clinical and Developmental Psychology, Loyola University Chicago. Received Ph.D. in Human Development from the University of Chicago. Current research interests include the developmental stage of adolescence with a focus on the daily experience of urban African American young adolescents and how this relates to their psycho- social well being. Dr. Richards served as a Predoctoral Adolescent Fellow (1979–1981) and Postdoctoral Adolescent Fellow (1984–1985) at the Clinical Research Training Program in Adolescence in Chicago, IL, which was co-directed by Dr. Daniel Offer., Loyola University Chicago, 6525 N. Sheridan Rd., Chicago, IL, 60626 USA Visiting Professor, Humphrey Institute of Public Affairs; President, University of Minnesota and Global Philanthropy Alliance. Received Ph.D. in Measurement, Evaluation, and Statistical Analysis from the University of Chicago. Research interest is in adolescent development. Dr. Petersen served as Coordinator of the Clinical Research Training Program in Adolescence (1978–1982) and Associate Director (1976–80) and Director (1980–82) of the Laboratory for the Study of Adolescence at Michael Reese Hospital and Medical Center (Chicago, IL) where Dr. Daniel Offer served as Director of the Department of Psychiatry. Dr. Petersen and Dr. Offer collaborated on numerous research papers while working together at Michael Reese Hospital., University of Minnesota and Global Philanthropy Alliance USA     

The personality correlates of differential verbal and mathematical ability in talented adolescents

This paper describes the personality correlates of differential verbal and mathematical ability in very bright adolescent boys (N=182). The results indicate that there are few mean personality differences between two groups of boys formed on the basis of high scores on measures of either verbal or quantitative ability. On the other hand, within each of these groups there are dependable personality correlates of differences between verbal and quantitative ability. In particular, boys with high verbal relative to their quantitative scores seem independent, rational, reflective, and mature, regardless of their vocational or academic preferences.Work on this paper was supported by a grant from the Spencer Foundation, Chicago, Illinois.Received her Ph.D. in psychology from the Johns Hopkins University. Major interests are personality theory and medical psychology.Received his Ph.D. in psychology from the Johns Hopkins University. Major interests are education and developmental psychology.Received his Ph.D. in psychology from the University of California at Berkeley. Major interests are personality theory and moral development.     

Selective attention and self-control in delinquent adolescents

Research studies are briefly reviewed to examine the hypothesis that delinquent adolescents may process information in a different manner than non-delinquents. Studies suggest that delinquents may have less control over which information they attend to, may expose themselves to more stimulation, may process information more slowly, and may selectively attend to different information than matched controls. Findings from a recent study are presented in support of the latter hypothesis. A clinical example illustrates how these attention differences may appear in the course of treatment.This work was conducted while Dr. Rosenthal was a Clinical Research Training Fellow in Adolescence in a program jointly sponsored by the Adolescent Program of the Illinois State Psychiatric Institute, the Institute for Psychosomatic and Psychiatric Research and Training at Michael Reese Hospital and Medical Center, and by the Departments of Behavioral Science (Human Development) and Psychiatry of the University of Chicago. The training program was funded by Public Health Service grant T32MH14668.A version of this paper was presented at the Conference on the Psychology of Adolescence, Chicago, June 20–21, 1980. Portions of this article are based upon the doctoral dissertation submitted by Frank Lani in partial fulfillment of the Ph.D. degree, Loyola University, Chicago, Illinois.Received his Ph.D. in clinical psychology at Vanderbilt University. Current research interests include delinquency, hyperkinesis, and evaluation of hospital treatment.Received his Ph.D. in clinical psychology at Loyola University. Current research interests include social cognition in delinquency.     

Risk and resilience in young adolescents

This exploratory study focused on the role of risk and protective factors in 179 adolescents from a middle and lower income northeastern school district. The protective factors examined were family cohesion, locus of control, mother/father communication, and relationship with a nonparent adult. The study found that the protective factors were powerful predictors of adaptation in their own right independent of risk. Protective factors were found to be highly context specific and there was no evidence of broadly applicable protective factors. Gender was found to be an important aspect of context, and there were significant sex differences. Most strikingly, the study did not find any significant interactions between protective factors and risk for girls or boys. Thus, these results support the growing view that researchers must identify specific rather than global protective factors that provide protection in the space of specific risks for youth in specific life contexts.A grant from the Boston University Graduate School provided initial support for this project.Received Ph.D. from Yale University in clinical psychology. Research interests include effects of risk, particularly sexual and physical abuse, and resiliency.Received M.A. from Boston University. Research interests include risk and developmental factors in psychopathology.Received Ph.D. in counseling psychology from Boston University Department of Psychology. Research interests include study of adolescence and risk factors.Received Ph.D. from Boston University.Received M.A. from Eastern Nazarine College, Quincy, MA.Received B.A. from Boston University Department of Psychology, Boston, MA 02215.     

Rorschach differences in normal and delinquent white male adolescents: A discriminant function analysis

Rorschach productions from 38 normal and 30 delinquent White male adolescents were scored by three Ph.D. clinical psychologists according to the method given by Beck. The groups were equated for IQ, social class, and age at the time of testing. Rorschach scales representative of various personality dimensions, i.e.,R, M, F, F+, FC, CF, C, FC: CF + C, Sum C, Affective Ratio, Shading, H, andA, were subjected to a linear discriminant analysis. The results showed highly significant and accurate differentiation between the groups (p<0.0005, correct classification rate =86.8%); however, theAffective Ratio was the only scale that heavily contributed to the discrimination. The difference between the groups on this scale was attributed to the delinquents' passive cognitive style. The results also lend support to the notion that delinquents differ from normals along the dimension of impulsivity, a finding relevant to psychodynamic theories of delinquency as reflective of serious ego deficits. Fuller consideration of Rorschach symbolic content and qualitative features of response is recommended.The first two authors' contributions were equal.Currently a Ph.D. candidate in education at Loyola University, Chicago. Major research interests are psychometrics, psychodiagnostics, and statistics.Received her Ph.D. in clinical psychology from Loyola University, Chicago. Major research interests are psychodiagnosis, psychotherapy evaluation, and the etiology of delinquency.Received his M.D. from Marquette University. Major research interests are juvenile delinquency and the process of psychotherapy.     

Physical activity and adolescent female psychological development

This study explored the relationship between self-reported past and present physical activity levels and high school adolescent women's self-image, sense of mastery, gender role identity, self-perceived physical ability, and self-perceived attractiveness. The Offer Self-image Questionnaire and the Bem Sex Role Inventory were administered to 149 high school adolescent women who were categorized as either physically active, physically inactive, decreasing in physical activity, or increasing physical activity. Results indicated the physically active group members reported self-image and coping characteristics that were significantly more positive than those reported by the physically inactive group members. They also reported significantly more masculine and feminine characteristics and higher physical ability ratings than inactive group members. The decreased activity group did not differ from any of the other groups. These results suggest that physical activity in adolescence, in comparison with physical inactivity, is associated with healthier emotional expression and emotional control, and higher levels of perceived mastery and coping skills for adolescent women. A decrease in physical activity over the course of adolescence does not necessarily result in psychological distress for adolescent women.Received Ph.D. in counseling psychology from Michigan State University. Major interests are concepts of the self, psychological health, and developmental psychology.Received Ph.D. in sport psychology from The Pennsylvania State University. Current research interests include social cognitions in sport and physical activity and the role of sport and physical activity in adolescent development.