A near-infrared variability study in the cloud IC1396W: low star-forming efficiency and two new eclipsing binaries

Identifying the population of young stellar objects (YSOs) in high extinction regions is a prerequisite for studies of star formation. This task is not trivial, as reddened background objects can be indistinguishable from YSOs in near-infrared colour-colour diagrams. Here we combine deep JHK photometry with J- and K-band lightcurves, obtained with UKIRT/WFCAM, to explore the YSO population in the dark cloud IC1396W. We demonstrate that a colour-variability criterion can provide useful constraints on the star forming activity in embedded regions. For IC1396W we find that a near-infrared colour analysis alone vastly overestimates the number of YSOs. In total, the globule probably harbours not more than ten YSOs, among them a system of two young stars embedded in a small (~10000 AU) reflection nebula. This translates into a star forming efficiency SFE of ~1%, which is low compared with nearby more massive star forming regions, but similar to less massive globules. We confirm that IC1396W is likely associated with the IC1396 HII region. One possible explanation for the low SFE is the relatively large distance to the ionizing O-star in the central part of IC1396. Serendipitously, our variability campaign yields two new eclipsing binaries, and eight periodic variables, most of them with the characteristics of contact binaries.Comment: 13 pages, 10 figures, MNRAS, in pres

Ingratiation Attempts in Real Life: Determinants of Their Success

A total of 272 students at a German university were asked to write down the story of an ingratiation attempt they had made and one they had received. They were then asked to reflect on each episode via a questionnaire. All but one participant reported that they had performed at least one of the four tactics postulated in Jones's ingratiation theory: compliments, favor-doing, opinion conformity, and positive self-presentation. In the case of received ingratiation, we found higher success ratings for nondependent (vs. dependent) partners, for just-being-friendly (vs. attraction-seeking) as the attributed motive, and for honest (vs. nonhonest) compliments and self-presentation. Female senders reported more success than did males (interpretable through existing research on gender differences). Finally, success levels were higher in the sender than in the receiver condition. Thus with our new autobiographical method we have extended the validity of three known determinants of the success of ingratiation attempts and discovered two novel factors deserving further research

Future orientation of institutionalized and noninstitutionalized delinquents and nondelinquents

In der hier vorliegenden Untersuchung wurden - ausgehend von Ansätzen der sozialen Lerntheorie - Zusammenhänge zwischen Zukunftsorientierung einerseits und Delinquenz und Institutionalisierung andererseits untersucht. 240 männliche Jugendliche (institutionalisierte und nichtinstitutionalisierte Delinquente und Nichtdelinquente) beantworteten offene und strukturierte Fragen hinsichtlich ihrer Zukunftserwartungen und -bewertungen. Die durch Varianzanalysen und t-Tests ausgewerteten Daten bestätigen z.T. die Hypothesen: Delinquente strukturierten ihre Zukunft weniger differenziert und langfristig und eher internal als Nichtdelinquente; dies traf insbesondere fUr die institutionalisierten Delinquenten zu. Delinquente strukturierten jedoch ihre Befürchtungen hinsichtlich Selbstverwirklichung stärker als Nichtdelinquente. Je nach Dauer der Institutionalisierung variiert die Zukunftsorientierung in verschiedenen Lebensbereichen. Diese Ergebnisse bestätigen nicht die in der Literatur vorherrschende Annahme einer unrealistischen Zukunftsorientierung von Delinquenten; hier zeigte sich vielmehr, daß institutionalisierte Delinquente eher negative zukünftige Ereignisse antizipieren, deren Auftreten sie für die Zeit nach ihrer Entlassung befürchten. Allerdings müssen die vorliegenden Befunde aufgrund der besonderen Stichprobe und der kurzen Institutionalisierungsdauer relativiert werden. Auch ist die hier verwendete Methode der differenzierten Erfassung von Zukunftsorientierung in der Literatur nicht üblich. Jedoch hat sich hier die Konzeptualisierung der Zukunftsorientierung als mehrdimensionales thematisch differenziertes Konstrukt als fruchtbar erwiesen

Group influences on probability judgments concerning social and political change

This study was intended to inquire into the generality of group-induced extremization (shift away from the neutral, middle point of a given response scale). The stimulus task for subjects was to estimate the probability that certain desired social, political, or economic conditions would exist by the year 2000. Another purpose of this study was to test the generality of the discussion-induced shift toward pessimism found in a previous study. Using nine discussion groups (size 3 or 4) and 13 control subjects (simple test-retest), the following findings were obtained. ( 1) Group means shifted toward higher extremity after discussion. (2) There was no shift when the extremity of group members' individual positions were compared. (3) The control subjects shifted toward less extreme judgments, and their judgmental confidence decreased. (4) No group shift toward pessimism was obtained. The discussion centers on subsidiary (correlational) evidence suggesting one cause of this group extremization was the disproportionate influence of extreme group members

Group versus individual performance on tasks requiring ideational proficiency (brainstorming): a review

In the experiments reviewed in this article the subjects are asked to produce ideas that are relevant to a given task request (e.g., possible consequences of a hypothetical event). After describing the specific task material and the performance measures used in the relevant research studies, some analytic background is given by outlining the cognitive resources required in this kind of experimental task and by listing the various factors that may come into play when subjects perform in groups (with discussion) instead of individually. We then review the studies comparing individual and group performance. In all ot these experiments the subjects were asked to work according to the rules of brainstorming, which prescribe that participants refrain from evaluating their ideas. This procedure purportedly results in superior group, relative to individual, performance. However, the empirical evidence clearly indicates that subjects brainstorming in small groups produce fewer ideas than the same number of subjects brainstorming individually. Less clear evidence is available on measures of quality, uniqueness and variety. The discussion considers factors that may be responsible for this inferiority of groups. The role of social inhibition receives particular attention also in terms of suggestions for research. Apart from the group-individual comparison we review the existing research concerning factors that may influence group performance on idea-generation tasks

Negotiation by leaders in the presence of their delegates and by delegates in the presence of their leaders

Following a preliminary testing session for assessing individual risk preferences on the choice-dilemmas task, subjects (8 at a time) were constituted as 4 leader-delegate dyads with status randomly assigned. Dyads reached joint decisions on half of the choice-dilemmas items. Subjects were then recombined as all-leader and all-delegate groups. For half of these combinations, leaders were discussants and delegates were observers; roles were reversed for the other half. The discussants' task was to negotiate a consensus on all of the choice-dilemmas items. Delegate discussants relative to leader discussants consulted more with their former dyadic partner and more often failed to achieve consensus (deadlock). Magnitude of risky shift did not differ significantly between leader and delegate discussants. However, delegate observers advocated higher risk levels than their leader discussants, whereas delegate discussants and leader observers did not differ in risk preferences. Discussant-observer discrepancies in risk preference were consistent with differences in decision satisfaction. On the whole, the presence of observers seems to increase “loss of face” motivation in leaders and fears of sanction for deviation in delegates.publishe

Negotiation constraints in the risk-taking domain: Effects of being observed by partners of higher or lower status

This study examined the effects of status held in a reference group and of prior issue commitment on the risky shift and other negotiation outcomes under conditions where accountability to the reference group during negotiation had been enhanced by having high and low status members observe each other. Following assessment of individual risk preferences on the choice-dilemmas task, subjects (eight at a time) were constituted as four leader-subordinate dyads and told to reach joint decisions on half of the choice-dilemmas items. Recombination as all-leader and all-subordinate groups followed. For half of each of these combinations, leaders were negotiators and subordinates were observers; role assignments were reversed for the other half. The negotiators' task was to achieve a consensus on all of the choicedilemmas items-both those with prior dyadic decisions and those without. It was found that subordinate negotiators, relative to leader negotiators, consulted more with their former dyadic partner and more often failed to achieve consensus (deadlock). Subordinate observers advocated higher risk levels than their leader negotiators, whereas subordinate negotiators and leader observers did not differ in risk preferences. Prior issue commitment increased the difficulty of a negotiated agreement and decreased decision satisfaction. On the whole, the presence of observers seemed to increase "loss of face" motivation in leaders and fears of sanction for deviation in subordinates

Risky shift as a function of group members' value of risk and need for approval

Eighty-eight female subjects were assigned to dyads homogeneously composed with regard to their valuation of risk acceptance (low or high) as well as their need for approval (low or high). The dyads discussed each of a set of hypothetical decision situations involving risk taking and, at the end of each discussion, indicated the risk levels acceptable for them. High-value dyads shifted significantly more toward risk, relative to their prior decisions (2 X 2 analysis of variance). As intended, the study demonstrates that risk as a value plays a causal role in the group risky-shift effect. Other results are brought to bear on the parsimony of recent formulations of the value theory of risky shift