Effects of component length and of the transitions among components in multiple schedules

Pigeons received equal variable-interval reinforcement during presentations of two line-orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among components.     

Relations between neonatal states and 8-month developmental outcome in preterm infants

This study investigated longitudinal relations between measures of neonatal state behavior and developmental outcome in a sample of preterm infants (N = 16). Results indicate that irritability/reactivity in the neonatal period is positively associated with Bayley scores and exploratory play at 8 months. Conversely, neonatal alertness was not associated with these developmental measures. These preliminary findings, based on a small sample, are discussed in the context of preterm function.     

Effects of neonatal treatment with 1-(2,5-dimethoxy-4-lodophenyl)-2 aminopropane HCI (DOI) and ritanserin on agonistic behavior in adult male and female rats

The role played by the neonatal 5-hydroxytryptamine (5HT) system in the organization and sexual differentiation of adult agonistic behavior was investigated in rats. Focus was on the 5HT2 receptor subtype, which has been demonstrated to be involved in agonism control in the adult. 5HT2 activity was experimentally manipulated by administration of a specific agonist [1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (DOI)] or antagonist (ritanserin) during the second week of life, when serotonin is known to concur to anatomical and behavioral sexual differentiation. Interactions between early 5HT2 activity, genetic sex, and neonatal circulating testosterone (T) were studied by administering the ligands to males, females, and androgenized females. At adulthood, the animals were tested for both aspects of agonism, i. e., aggression and defense, in a 20-min confrontation with an unfamiliar conspecific of the same sex, age, body weight, and social experience. Neonatal administration of the 5HT2 antagonist ritanserin increased aggression independently of sex; it also increased defense, but this effect was confined to males. The agonist DOI had no effect on aggression, but enhanced defense in males and androgenized females, with an effect which depended therefore more on neonatal T than genetic sex. Females appeared in general less sensitive to neonatal 5HT2 manipulation than both androgenized females and males; this suggests that neonatal T is crucial for experimental modifications of neonatal 5HT2 activity to have any consistent effect on adult agonistic behavior. On the other hand, effects observed in males and androgenized females were dependent on the behavior considered and the drug administered. This was especially evident for defense, enhanced by ritanserin in males only, and in both males and androgenized females by DOI. Neonatal 5HT2 activity seems therefore to play a role in the modulation of adult agonistic behaviors, which depends on the behavior considered and is under multiple control of genetic sex and hormonal neonatal substrate. © 1994 Wiley-Liss, Inc.     

Determinants of ethnic identity development in adulthood: A longitudinal study

Ethnic identity is defined in terms of the interaction between exploration of and commitment to a given cultural background. The present study investigated the effect of individual background, role transitions, and the social environment on the development of ethnic identity in a sample of German adults aged 21–73 years (N = 2,940). Additionally, identity transitions and the moderating effect of disequilibrating life events on identity over time were examined (N = 827). Overall, results are consistent with findings for other identity domains: Respondents could be assigned to one of four identity stages, ranging from unexamined to achieved identity. Particularly, the individual background and the extent of community involvement affected ethnic identity formation in adulthood. Longitudinal analyses revealed that only one-third of respondents had remained in the same identity stage; most individuals had transitioned forward or backward. Changes in ethnic identity were not moderated by disequilibrating life events.     

Maternal and paternal infant representations: A comparison between parents of term and preterm infants

Objective

Research on parental attachment representations after preterm birth is limited and inconclusive. The present study is the first in which maternal and paternal attachment representations after term, moderately and very preterm birth are compared. In addition, special attention was directed toward disrupted attachment representations.

Method

Mothers and fathers of term infants (≥37 weeks of gestational age, n = 71), moderately preterm infants (≥32–37 weeks of gestational age, n = 62) and very preterm infants (<32 weeks of gestational age, n = 56) participated in the present study. Attachment representations (balanced, disengaged, distorted) about their infants were evaluated with the Working Model of the Child Interview (WMCI). To asses disrupted representations the coding of the WMCI was extended with the disrupted scale (WMCI-D).

Results

The three main classifications of attachment representations were not affected by preterm birth. In addition, there were no gender differences in the rate of balanced representations. In case of non-balanced representations however, maternal representations were more often distorted, whereas fathers showed more often disengaged representations. Results further revealed that maternal disrupted attachment representations were marked by role/boundary confusion or disorientation, whereas paternal disrupted attachment representations were characterized by withdrawal.

Conclusion

Given the gender differences it is essential to tailor interventions according to the attachment representations of the parent, in order to be able to alter their non-balanced and/or disrupted attachment representations.     

Adult Attachment Dimensions,World View Schemas,and the Psychological Health of Parents of Infants in a Neonatal Intensive Care Unit

This study reports the results of an exploration of the relationship of adult attachment dimensions (closeness, dependence, and anxiety) and world view assumptions (benevolence, meaningfulness, and worthiness) to psychological distress and psychological well-being in 142 parents (71 couples) of newborns recently hospitalized in a neonatal intensive care unit. The results of the Actor-Partner Interdependence Model, hierarchical multiple regression, and mediation analyses showed that parents who were more comfortable with attachment-dependence and parents who held more positive beliefs about benevolence and worthiness had less psychological distress and more well-being. In addition, parents with partners who were more comfortable with attachment-dependence had less psychological distress and more well-being. Attachment-dependence partially mediated the relationships of benevolence and worthiness with psychological distress and the relationship of benevolence with psychological well-being, whereas worthiness had a direct relationship with psychological well-being.     

“How can you make friends if you don't know who you are?” A qualitative examination of international students' experience informed by the Social Identity Model of Identity Change

This paper explores the contribution of social identity change to international students' health and well‐being. International students typically face a range of challenges from the time they leave their home country, including the need to adapt both to a new culture and norms and to a new educational landscape. Previous research informed by the Social Identity Model of Identity Change (SIMIC) suggests that during such life transitions, an individual's group memberships and associated social identities can provide a buffer against the threats to well‐being that such transitions present. To examine the relevance of SIMIC for the transitions that international students' experience, semistructured interviews were conducted with 15 international students attending an Australian university. Thematic analysis provided support for the relevance of SIMIC's social identity gain and social identity maintenance pathways in the transition and revealed a number of associated factors that acted as either facilitators (e.g., a host family that supported community integration) or barriers (e.g., experiencing culture shock) to social identity change. These findings present the first qualitative support for SIMIC within an international student population and help to flesh out the specific ways in which social identity processes contribute to both positive and negative health and well‐being outcomes.     

Extracurricular Participation and Course Performance in the Middle Grades: A Study of Low-Income,Urban Youth

The transition to middle/junior high school is associated with declines in students’ academic performance, especially among low‐income, urban youth. Developmental psychologists posit such declines are due to a poor fit between the needs of early adolescents—industry, identity, and autonomy—and the environment of their new schools. Extracurricular participation during these years may act as a buffer for youth, providing a setting for development outside the classroom. The current study examines participation within and across activity settings among low‐income, urban youth in New York City over this transition. Using the Adolescent Pathways Project data, this study explores how such participation relates to course performance. We find that a large percentage of youth are minimally or uninvolved in extracurricular activities during these years; that participation varies within youth across time; and that the association between participation and course performance varies by activity setting. Youth who participate frequently in community or athletic settings or have high participation in two or more settings are found to have higher GPAs in the year in which they participate and youth who participate frequently in the religious setting are found to have lower GPAs. High participation in more than two settings may be detrimental.     

Public Storylines in the British Transition from Rail to Road Transport (1896–2000): Discursive Struggles in the Multi-Level Perspective

ABSTRACT

An analysis of the transition from railways to highways as the dominant British transport system during the twentieth century shows that public storylines about competing niche and regime technologies can have a powerful influence on socio-technical transitions. These storylines are developed by supporters and opponents of the competing technologies, with each group attempting to frame their favoured technology positively. The public salience of these storylines can be evaluated by assessing how highly they score on four elements of frame resonance: empirical fit, experiential commensurability, actor credibility, and macro-cultural resonance. These storylines can be seen at play across the entirety of the transition to a road-based transport system, from the very early history of the automobile through to the turn of the millennium, when public opposition to road transport was becoming increasingly pronounced. This case study uniquely traces discursive conflict over the entire course of a multi-decade transition. While existing literature in the multi-level perspective typically emphasises the disadvantages faced by niche-innovations, this case study shows that powerful storylines, enabled by the right cultural repertoires and possibly negative storylines about existing socio-technical systems, can create powerful political support for a new technology, giving it an advantage against more established incumbents.