Hormones and aggression in childhood and adolescence

This review is a survey on recent psychobiosocial studies on association between hormones and aggression/violence in children and adolescents, with a special focus on puberty, given the rapid changes in both hormones and behavior occurring during that developmental period. Since it cannot be assumed that all readers have much background knowledge, it inevitably begins with some comments about the concept and multifaceted nature of aggression, as well as with a brief reminding about hormone candidates to be linked to aggression during human development. Then, we finish off with the status of its knowledge in today's science, tackling in a systematic way with the main data published, hormone by hormone. The origin of the gender-based differences in aggression must lie in neuroendocrinological events occurring during prenatal life or early in postnatal life. A complex and indirect effect of testosterone on aggression is proposed. A low HPA axis activity seems associated with chronic aggressive and antisocial behaviors. It is also suggested that early adrenal androgens contribute to the onset and maintenance of persistent violent and antisocial behavior, and that it begins early in life and persists into adulthood, at least in young boys. There are also some studies suggesting an association between aggression and some pituitary hormones in children, even if present data are still far from being consistent. The hormone-aggression link during development thus is not consistently reported. There can be an indirect relation in three ways: hormones can be involved in the development of aggression as a cause, as a consequence, or even as a mediator. Psychosocial factors may influence the causation and progression of violence in children through hormonal action.     

Electroencephalographic and dichotic indices of cerebral laterality in stutterers

To test the hypothesis that stuttering is the product of faulty cerebral laterality four experiments were performed on each of five adult stutterers and five fluent speakers. These tests were: (1) dichotic listening with consonant-vowel pairs, (2) alpha recording over both hemispheres during the performance of cognitive tasks intended to engage preferentially the left or right hemispheres, (3) contingent negative variation with either an articulatory or bilaterally symmetrical response, and (4) readiness potential with the same responses. The results fail to disconfirm the null hypothesis regarding stutterers and their fluent peers. All subjects showed consistent patterns of cerebral laterality indicative of localization of speech function in the left hemisphere. Suggestions are made regarding a possible contribution of deficient sensorimotor integration in stuttering.     

Determinants of memory development in childhood and adolescence

Research on the development of memory has a long history and constitutes one of the most active research areas in the field of cognitive development. In this article, we first describe major historical developments in the literature on children's memory, focusing on systematic research that began in the late 1960s. We then examine new developments in the field, describing four important lines of inquiry: (a) the development of implicit memory, (b) short‐ and long‐term memory development in infancy, (c) longitudinal research on memory strategies and metamemory, and (d) developmental cognitive neuroscience of memory. Finally, promising lines of future research on memory development are briefly discussed.     

The development of gyrification in childhood and adolescence

Gyrification is the process by which the brain undergoes changes in surface morphology to create sulcal and gyral regions. The period of greatest development of brain gyrification is during the third trimester of pregnancy, a period of time in which the brain undergoes considerable growth. Little is known about changes in gyrification during childhood and adolescence, although considering the changes in gray matter volume and thickness during this time period, it is conceivable that alterations in the brain surface morphology could also occur during this period of development. The formation of gyri and sulci in the brain allows for compact wiring that promotes and enhances efficient neural processing. If cerebral function and form are linked through the organization of neural connectivity, then alterations in neural connectivity, i.e., synaptic pruning, may also alter the gyral and sulcal patterns of the brain. This paper reviews developmental theories of gyrification, computational techniques for measuring gyrification, and the potential interaction between gyrification and neuronal connectivity. We also present recent findings involving alterations in gyrification during childhood and adolescence.     

Children's competence and value beliefs from childhood through adolescence: growth trajectories in two male-sex-typed domains

The purpose of this study was to document gender differences in children's competence and value beliefs (N =514) from the 1st through 12th grades and to investigate the relation of these trends to initial differences in parents' perceptions of children's ability. Six separate growth models were tested: math competence, math interest, math importance, sports competence, sports interest, and sports importance. Across all 6 models, children's self-perceptions declined from 1st grade to 12th grade. Gender differences in competence and value beliefs were found. The gap between boys' and girls' competence beliefs decreased over time. In addition, parents' initial ratings of children's ability helped to explain mean level differences and variations in the rate of change in children's beliefs over time, with the effect being strongest in the sports models.     

Functional and dysfunctional impulsivity in childhood and adolescence

There are few self-reports of impulsivity dealing with children, although this personality trait has been related to many behaviour problems in both children and adolescents. The appropriateness of the Dickman Impulsivity Inventory for Children (DII-c) and the Dickman Impulsivity Inventory (DII) to measure impulsivity in children and adolescents was assessed. The factorial structure of the DII-c and the internal consistencies for both inventories suggest the measured dimensions are not consistent until adulthood. These self-report measures are not appropriate for children and adolescents.     

Friendship stability and change in childhood and adolescence

The objective of this review is to focus on a neglected aspect of children’s and adolescents’ friendships: the level of temporal stability. First, a rationale for examining stability as a distinct friendship dimension is presented. Next, the different levels of friendship experiences are distinguished. Friendship stability is also discussed across developmental periods. Factors affecting friendships stability and individual correlates associated with friendship stability are then covered. Finally, the methodological issues pertaining to the study of friendship stability are addressed. The authors conclude by emphasizing the importance of pursuing future research that aims to demonstrate the pertinence of the friendship stability construct as an individual difference variable. Further, on a methodological level, the assessment of stability needs to be based on longitudinal designs that include multiple measurement waves. Ultimately, such detailed analysis of stability will allow a better understanding of the dynamic processes by which friendships change over time and affect children’s and adolescents’ psychosocial development.     

Electroencephalographic and rheoencephalographic studies of cerebral meningovascular tumors

For forty-one meningovascular tumors, which were verified pathologically and anatomically, the authors tried to find electroencephalographic and rheoencephalographic criteria of the recognition of the location and particular kind of tumor. Electroencephalographic results obtained for meningovascular tumors are characterized by insignificant to moderate general and focal alterations. The results of rheoencephalographic examinations were found to add to the possibilities of topical diagnosis. Angioarchitectural characteristics of the rheoencephalographic curve, together with bioelectric phenomena, enabled a specific diagnosis to be established for twenty-four of the meningovascular tumors.     

Sociology and psychology within the scope of scientific dishonesty

A survey is undertaken based on qualitative analyses of the cases of scientific misconduct from the Danish Committee on Scientific Dishonesty’s first five years of collecting data, with additional information from selected international sources, in which underlying psychological motivations can be judged. An carlier version of this paper was presented at a symposium, Scientific Misconduct. An International Perspective, organised by The Medical University of Warsay, 16 November, 1998.     

Depressive syndromes within the scope of schizophrenic diseases

The results of a standardized examination of 135 schizophrenics shows that the "depressive factor" is less pronounced during differential neuroleptic therapy (Clozapin, Haloperidol) and in the control group of schizophrenics receiving no drug treatment. This suggests that the depressive syndrome among schizophrenics is not manifested as a result of pharmaceutical action. The author proposes that neuroleptic therapy tailored to the patient can ameliorate the depressive syndrome observed in schizophrenics. Both psychoreactive and disease specific factors may play a role in the pathogenesis of depression among patients with this disease.     

Clinicogenetic studies within the scope of Leonhard taxonomy

Using conventional genealogical methods and genetic correlation analysis, the author investigates Leonhard's classification of schizophrenias and cycloid psychoses. According to the second of these methods, the systematic schizophrenias and cycloid psychoses definitely diverge on account of the phenotypic correlations, whereas the unsystematic group presumably occupies a median genetic position between the two categories first mentioned.     

Five types of personality continuity in childhood and adolescence

This study examines 5 types of personality continuity--structural, mean-level, individual-level, differential, and ipsative--in a representative population (N=498) and a twin and sibling sample (N=548) of children and adolescents. Parents described their children on 2 successive occasions with a 36-month interval using the Hierarchical Personality Inventory for Children (I. Mervielde & F. De Fruyt, 1999). There was evidence for structural continuity in the 2 samples, and personality was shown to be largely differentially stable. A large percentage had a stable trait profile indicative of ipsative stability, and mean-level personality changes were generally small in magnitude. Continuity findings were explained mainly by genetic and nonshared environmental factors.     

Early symptoms in schizophrenic patients in childhood and adolescence

The work deals with the observation of courses of 26 cases of schizophrenia in childhood and youth treated in the children's departement of the district mental hospital of Uchtspringe from 1975 to 1982. Two thirds of the total number were conspicuous by characteristics of an organic brain damage and broken homes before going to school, partly already in infancy.