Modeling continuity and discontinuity in utterance length: a quantitative approach to changes, transitions and intra-individual variability in early grammatical development

The confluence of an anomaly such as a growth spurt or a temporary regression on the one hand and a temporary increase in intra-individual variability on the other hand, forms a strong indicator of a major transition in early language development. Data concern one-word (W1), two- and three-word (W2-3), and four-and-more-word (W4+) utterances from two French children during their second and third years. A dynamic growth model was fitted, based on a structure of supportive, conditional and competitive relationships. Using a statistical simulation method, we showed two striking peaks of variability in addition to a temporary regression or rapid growth in the proportions of W1, W2-3 and W4+ utterances. We argue that these phenomena show transitions corresponding to critical points in grammatical development, which could be indicative of the emergence of simple combinatorial and syntactic stages of language successively. Our results emphasize the relevance of time-serial data and of intra-individual variability in the study of developmental transitions in general.     

Planning and on-line control of catching as a function of perceptual-motor constraints

Two experiments were conducted in order to investigate the adaptability and associated strategies of the human perceptuo-motor system to deal with changing constraints. In a catching task, perceptual-motor constraints were internally controlled by coupling movement onset of the catch and the illumination circuit in the lab: upon the first movement of the catcher, all lights went out within 3 ms. The authors studied (a) how much movement time catchers prefer if no visual information is available after movement onset, and (b) how movement execution changes under such temporal constraints. It was hypothesised that, in order to accomplish successful catching behaviour, (1) movement initiation would be postponed in order to allow sufficient information uptake before the lights went out, and (2) an alternative control strategy would have to be mobilised, since on-line control becomes inappropriate when catching in the dark. In the first experiment, the adaptation process to the light-dark paradigm was investigated. In the second experiment, the conclusions from experiment 1 were challenged under varying ball speeds. In order to maintain catching performance, subjects initiated the catch approximately 280 ms before ball-hand contact. Next to changes in temporal structure of the catch and subtle kinematic adaptations, evidence for a change in the control mode emerged: while an on-line control strategy was adopted under normal illumination, catching movements seemed to be executed as planned in advance when catching in the dark. Additionally, perceptual constraints seem to determine the time of movement initiation, rather than motor constraints. These results emphasize the capability of the human perceptuo-motor system to adjust promptly to new task constraints.     

Contribution of content, context, and process to understanding openness to organizational change: two experimental simulation studies

The authors examined the contribution of the content, context, and process of organizational transformation to employees' openness to change. The authors predicted that 5 factors would have a positive effect on openness to change: (a) threatening character of organizational change (content related), (b) trust in executive management (context related), (c) trust in the supervisor (context related), (d) history of change (context related), and (e) participation in the change effort (process related). The authors tested their hypotheses in 2 separate studies (N = 828 and N = 835) using an experimental simulation strategy. The first study crossed 4 variables in a completely randomized 2 x 2 x 2 x 2 factorial design. Results showed significant main effects for content, context, and process but no significant interaction effects. A second study, with a completely randomized 2 x 2 factorial design, crossed two context variables. Results showed a significant main and an interaction effect: Openness to change decreased dramatically only when history of change and trust in executive management were low.     

The Dynamics of General Developmental Mechanisms: From Piaget and Vygotsky to Dynamic Systems Models

Dynamic systems theory conceives of development as a self-organizational process. Both complexity and order emerge as a product of elementary principles of interaction between components involved in the developmental process. This article presents a dynamic systems model based on a general dual developmental mechanism, adapted from Piaget and Vygotsky. The mechanism consists of a conservative force, further strengthening the already-consolidated level, and a progressive force, consolidating internal contents and procedures at more advanced levels. It is argued that this dual mechanism constitutes one of the few basic laws of learning and change, and is comparable to the laws of effect and of contiguity. Simulation studies suggest that this dual mechanism explains self-organization in developmental paths, including the emergence of discrete jumps from one equilibrium level to another, S-shaped growth, and the occurrence of co-existing levels.     

What's in it for Me? Motivational Differences between Farmers' Subsidised and Non‐Subsidised Conservation Practices

Through nature conservation practices, farmers can strongly enhance nature quality and biodiversity in rural areas. In this paper, the social psychological underpinnings of farmers' nature conservation practices are investigated using the Theory of Planned Behavior, to which the concepts of self‐identity and personal norms were added. A distinction is made between nature conservation practices done on a non‐subsidised basis and nature conservation practices for which farmers receive some form of remuneration from the Dutch government. Eighty‐five arable farmers participated in our survey. Results show that our model explains more variance in the intention to perform non‐subsidised than subsidised nature conservation practices. Also, the concepts of self‐identity and personal norms appear to be related to the intention to perform non‐subsidised, not subsidised conservation.     

A European in Asia†

How culture‐proof are the social sciences? Travelling in another continent, one meets culture's influences not only in the objects of social science research, but at least as much in the minds of the researchers. Researchers' problem definitions and choices of issues to be addressed and questions to be asked limit what they will find; they are a potential source of ethnocentric bias. A case example of the discovery of such a bias was the emergence of a fifth dimension of national cultures supplementing Hofstede's four, through Bond's Chinese Value Survey. In the area of personality research, a number of newer and older findings by Asian and European researchers suggest the need for expanding the ‘Big Five’ model of personality traits with a sixth factor, Dependence on Others, in order to make the model culturally universal. In general, researchers recognize primarily those aspects of culture for which their own culture differs most from others. For escaping from the cultural constraints in our own research we therefore need to trade ideas with colleagues from other parts of the world. In this respect, Asian researchers have an important role to play.     

Studies on wild house mice VI: Differential effects of the Y chromosome on intermale aggression

The aim of this study is to determine the effects of different parts of the Y chromosome of wild house mice on aggression. To reach this goal, intercrosses were made between two selection lines for attack latency (SAL and LAL) and their congenic strains (SAL. LY and LAL. SY). This procedure resulted in F₁ hybrids that carried the same autosomes, but differed in their X chromosome and the two different parts of their Y chromosomes, the different parts of the Y chromosome being a recombining part called the pseudoautosomal region (PAR) and a non-recombining part (non-PAR). We conclude that both parts of the Y chromosome contribute slightly but significantly to variation in aggression. The major effect is accomplished by the PAR of the aggressive parent; a mirror effect is achieved by the non-PAR of the aggressive parent in interaction with the PAR. © 1994 Wiley-Liss, Inc.     

Studies on wild house mice iv: On the heredity of testosterone and readiness to attack

An attempt was made to determine the role of the Y chromosome in the development of aggression in wild house mice. The aggression-eliciting property of testosterone depends not only on circulating adult testosterone, but also on perinatal sensitization of the central nervous system to this steroid. Results of crosses between aggressive (SAL) and non-aggressive (LAL) mice indicate that adult plasma testosterone in these mice is determined by the autosomes, high testosterone levels being dominant over low levels. Conversely, the Y-chromosomal effect seems related to perinatal processes that sensitize the brain for testosterone.     

Treatment Effect on Recidivism for Juveniles Who Have Sexually Offended: a Multilevel Meta-Analysis

The current study investigated the effect on recidivism of treatment aimed at juveniles who have sexually offended. It also assessed the potential moderating effect of type of recidivism, and several treatment, participant and study characteristics. In total, 14 published and unpublished primary studies, making use of a comparison group and reporting on official recidivism rates, were included in a multilevel meta-analysis. This resulted in the use of 77 effect sizes, and 1726 participants. A three-level meta-analytic model was used to calculate the combined effect sizes (Cohens d) and to perform moderator analyses. Study quality was assessed with the EPHPP Quality Assessment Tool for Quantitative Studies. A moderate effect size was found (d = 0.37), indicating that the treatment groups achieved an estimated relative reduction in recidivism of 20.5% as compared to comparison groups. However, after controlling for publication bias, a significant treatment effect was no longer found. Type of recidivism did not moderate the effect of treatment, indicating that treatment groups were equally effective for all types of recidivism. Also, no moderating effects of participant or treatment characteristics were found. Regarding study characteristics, a shorter follow up time showed a trend for larger effect sizes, and the effect size calculation based on proportions yielded larger effect sizes than calculation via mean frequency of offending. Implications for future research and clinical practice are discussed.