bluuebunny/crossref_metadata_2025 huggingface dataset:
Depression and Judgment of Control: Impact of a Contingency on Accuracy
Authors: Tang Catherine So‐kum , Critelli Joseph W.
Published: April 2006

ABSTRACT In this study we sought to determine whether mild depressives and nondepressives could respond adaptively and self‐correct their judgments of contingency when it was clearly advantageous to do so Ninety‐six undergraduates were given four contingency‐learning tasks involving pressing or not pressing a key to turn on a light and to judge the degree of control their responses had over light onset On the first task, which included a monetary contingency only on light onset, mild depressives were relatively accurate in their judgments of control Tasks 2 through 4, which also included a monetary contingency and feedback on accuracy of judgment of control, showed a Mood x Task interaction Mild depressives, but not nondepressives, became more accurate, and by the last task, mild depressives were more accurate than nondepressives Results were discussed in terms of incentive, feedback, and task exposure
Self‐Consciousness and Strategic Self‐Presentation
Authors: Doherty Kevin , Schlenker Barry R.
Published: April 2006

ABSTRACT
People who are publicly self‐conscious have been characterized as being especially concerned about their social identities and oriented toward gaining approval and avoiding disapproval. In two experiments, it was found that “pure publics” (i.e., those high in public and low in private self‐consciousness) were the most concerned about matching their deeds and words. These subjects presented themselves to a partner consistently with their publicly known, prior performance on a supposedly valid test of social sensitivity. However, they presented themselves in a uniformly positive manner if the test could be dismissed as invalid and/or if their performance was unknown. In contrast, subjects low in public or high in private self‐consciousness did not display these strategic patterns and presented themselves positively in all cases. Pure publics are thus the most likely to engage in patterns of self‐presentation that have been shown to maximize approval and minimize disapproval in social interactions.
The Development of the Sense of Self in Adolescence
Authors: Blasi Augusto , Milton Kathy
Published: April 2006

ABSTRACTThis study attempts to clarify the sense of self that may underlie the adolescent's subjective experience of identity. The initial orientation was / provided by descriptions of three different modes of experiencing identity derived from a reanalysis of Loevinger, Wessler, and Redmore's (1970) ego development categories. Our goal was to replicate by a more direct method the Loevinger‐derived descriptions. Specifically, we looked at whether the various aspects of the pre‐identity mode (“Social Role identity”) and of the early identity mode (“identity Observed”) would in fact form different clusters and j whether these clusters would differentiate early and middle adolescent groups. Participants were 24 sixth graders and 24 high‐school seniors, equally divided by sex. In individual inter views they were asked questions concerning the main characteristics of the identity Observed Mode. Six self scales were constructed from subjects' responses. Our two major hypotheses were strongly supported: (a) The two age groups differed dramatically on each of the self scales; and (b) the six self scales highly correlated with each other. Moreover, clusters of responses could be constructed that model the a priori descriptions of identity modes and that sharply separate the two grades.
Public Confession and Forgiveness
Authors: Weiner Bernard , Graham Sandra , Peter Orli , Zmuidinas Mary
Published: April 2006

ABSTRACT
In this article, we report investigations of four role‐playing experiments and one laboratory manipulation that examine the effects of confession on forgiveness and other related judgments. The basic paradigm in the simulation studies was to reveal that a political figure or student in a class confessed either following or not following an accusation, or denied personal responsibility for the act. Among the variables manipulated were the attributions for the wrongdoing and the spontaneity of the confession. The dependent variables in one or more investigations included the perceived personal character of the trangressor, attributions of responsibility for the act, affective reactions of sympathy and anger, forgiveness, and behavioral judgments such as sanctioning and voting likelihood. In the laboratory manipulation study, a mixed‐motive game setting was used in which a confederate confessed to having prior knowledge that resulted in his winning the game. We then examined whether this admission influenced subsequent cooperation and competition, as well as the other players' perceptions of the confederate's personality and character. Confession was found to have strong beneficial effects, particularly when given without a prior accusation and in ambiguous causal situations.
Conflict in Married Couples: Personality Predictors of Anger and Upset
Authors: Buss David M.
Published: April 2006

ABSTRACT
This research had two central goals: to examine the role of personality in (a) performing actions that anger spouses, and (b) eliciting anger‐provoking actions from spouses. Personality data on a sample of married persons (N= 214) were obtained from three sources—self‐report, spouse‐observer report, and independent interviewers' reports. In a separate session, subjects recorded which of 147 upsetting actions their spouses had performed in the past year. A series of hierarchical multiple regressions revealed the effects of Surgency, Agreeableness, Conscientiousness, Emotional Stability, and Intellect on evoking upset in spouses through condescension (e.g., treating spouse as stupid or inferior), possessiveness (demanding too much time and attention), abuse (slapping spouse), unfaithfulness (having sex with others), inconsiderateness (leaving toilet seat up), moodiness (crying a lot), alcohol abuse (drinking too much alcohol), emotional constriction (hiding emotions to act tough), and self‐centeredness (acting selfishly). Discussion of this research focuses on the implications of personality for conflict in marital relationships.
Parent‐Offspring and Sibling Adoption Analyses of Parental Ratings of Temperament in Infancy and Childhood
Authors: Plomin Robert , Coon Hilary , Carey Gregory , DeFries J. C. , Fulker David W.
Published: April 2006

ABSTRACT
A first step toward understanding the etiology of personality is to investigate the relative impact of genetic and environmental factors using twin and adoption designs. Twin studies of infants and young children indicate substantial genetic influence for parental ratings of temperament in the preschool years. Adoption studies, however, have not previously been reported during the early years of life. We present parent‐off spring comparisons for temperament (emotionality, activity, sociability, and impulsivity) for adopted and nonadopted children yearly from 1 to 7 years of age and their biological, adoptive, and nonadoptive parents. Also presented are correlations for adoptive and nonadoptive siblings when each child was 1, 2, 3, and 4 years of age. In contrast with twin results, little evidence is found for genetic influence. The average correlation between biological parents and their adopted‐away children for data averaged over the 7 years is only .03. Similarly, the average parent‐off spring correlation in nonadoptive families (.08) is no greater than in adoptive families (.12). Results for nonadoptive and adoptive siblings also indicate little genetic influence. The difference between the twin and adoption results may be due to environmental effects or to nonadditive genetic variance.
An Implicit Theory of Intelligence‐Related Mental Activities
Authors: Hoskens Machteld , De Boeck Paul
Published: April 2006

ABSTRACT
Mental act verbs are used to study implicit theories of intelligence as represented by mental activities. First, the multidimensional structure of the verbs was studied using a sorting task. The resulting structure was interpreted primarily in terms of three properties: a working property that refers to the operational aspect of information processing (and that is closely related to depth of a cognitive activity), a judgment property, and a creativity property. Second, the notion of intelligence was projected onto the structure, rating the verbs to determine how much intelligence they represented. We discovered that mental activities scoring high on intelligence were related primarily to the working property and to in‐depth processing.
Effects of Self‐Consciousness and Social Anxiety on Self‐Disclosure among Unacquainted Individuals: An Application of the Social Relations Model
Authors: Reno Raymond R. , Kenny David A.
Published: April 2006

ABSTRACT Recent research has demonstrated a positive relationship between private self‐consciousness and the tendency to self‐disclose. These studies have relied exclusively upon self‐reports of disclosure. In the present study, Kenny's Social Relations Model (Kenny & La Voie, 1984) was employed to examine the relationship between a subject's self‐reports and others' reports of a subject's level of self‐disclosure and the relationship of these reports to private self‐consciousness, as well as the other traits measured by the self‐consciousness scale: public self‐consciousness and social anxiety. Unacquainted college women (N= 102) participated in one‐on‐one interactions in a round‐robin design. Subject's self‐reports of disclosure and their levels of private self‐consciousness correlated positively. The partners' reports of an individual's disclosure, however, were not related to the individual's level of private self‐consciousness. The discrepancy between these correlations emphasizes the necessity to ground research in personal relationships on interacting pairs and not only on the self‐reports of one member. Future research that would explore this difference is discussed. The examination of the self‐and partner reports and subjects' levels of public self‐consciousness and social anxiety demonstrated that these two traits significantly influence the acquaintance process. Public self‐consciousness related positively to subjects' beliefs that they had created consistent impressions upon their partners. Social anxiety correlated negatively with partners' reports of a subject's dyadic involvement and openness.
Gender, Appraisal, and Coping: A Longitudinal Analysis
Authors: Ptacek J. T. , Smith Ronald E. , Zanas John
Published: April 2006

ABSTRACT For 21 consecutive days, 186 male and female college students recalled the most stressful event of the day, recorded how the event was appraised, and indicated the coping methods they employed as well as their perceived effectiveness and the sequence in which they were used. Gender differences in seven coping strategies were examined in terms of frequency of use, extent of use, relative use, and the frequency with which each method was used first in the coping sequence. The gender differences that emerged were consistent with a socialization hypothesis that predicts more problem‐focused coping in men and more use of support seeking and emotion‐focused coping in women. Both men and women rated problem‐focused coping responses as more generally effective than seeking social support, and the latter as more effective than emotion‐focused coping responses. Additionally, we explored the roles of stressor type and of threat, challenge, and control appraisals in the observed gender differences.
The Assessment of Complexity of Representations of People Using TAT and Interview Data
Authors: Leigh Janet , Westen Drew , Barends Alex , Mendel Matthew J. , Byers Steven
Published: April 2006

ABSTRACT The complexity of mental representations of self and others is a central dimension of personality structure and interpersonal functioning. The richness, differentiation, and integration of representations develops throughout childhood and adolescence and differs among individuals and among various psychopathological populations. The nature and development of mental representations is central to object relations theories in psychoanalysis, and has been receiving empirical attention in the social cognition literature. This article reports the development of instruments for measuring the complexity of mental representations from narrative data, based on an integration of object relations and social cognition research. The present study provides preliminary support for the validity of two measures, one for use with the TAT, and the other for use with interview data such as research interviews, psychotherapy transcripts, and early memories.
Stability of Self‐Esteem: Assessment, Correlates, and Excuse Making
Authors: Kernis Michael H. , Grannemann Bruce D. , Barclay Lynda C.
Published: April 2006

ABSTRACT
We examined stability and level of self‐esteem as predictors of excuse making; the extent to which self‐ratings of stability are related to a statistical index of self‐esteem stability; and the relations between stability and certainty of self‐esteem and a variety of other psychological constructs. Regarding excuse making, our findings indicated that for high self‐esteem individuals, instability was related to greater excuse making following success, but not following failure. However, for low self‐esteem individuals, instability was related to greater excuse making following failure, but not following success. Other findings indicated that self‐ratings of stability were only minimally related to a statistical measure of stability based on repeated assessments of self‐esteem obtained in naturalistic contexts. Finally, stability of self‐esteem was not significantly correlated with certainty of self‐esteem. In addition, the pattern of correlations that emerged between certainty and other constructs suggested that uncertainty reflects the phenomenal experience of a tenuous self‐view. On the other hand, stability of self‐esteem appears to reflect the extent to which one's self‐view is malleable, which may not be completely available to conscious awareness. Our discussion focuses on the nature of self‐esteem stability and the roles of stability and level of self‐esteem in reactions to evaluative events.
A Problem of Personality: Scientist and Practitioner Differences in Psychology
Authors: Zachar Peter , Leong Frederick T. L.
Published: April 2006

ABSTRACT
Differences between scientists and practitioners have been one of the most consistent and controversial topics throughout the history of American psychology. Even though many qualitative arguments and indirect quantitative studies have been offered in the literature, scientist and practitioner personality perspectives have never been measured directly. We have done so in this study, and we argue that these differences can be conceptualized within a personality framework. Results of our study demonstrate that interest in scientist activities and interest in practitioner activities were both predicted by theoretical orientations and vocational personality styles. Scientist and practitioner interests were predicted by these variables in opposite directions. We conclude by noting that while the conflict between scientist and practitioner personality styles is often said to be solvable by appropriate education, training models provide only partial solutions. It would be useful for training models to examine the role of personality differences in scientist‐practitioner orientations in order to design realistic programs and objectives.
Folk Concepts, Natural Language, and Psychological Constructs: The California Psychological Inventory and the Five‐Factor Model
Authors: McCrae Robert R. , Costa Paul T. , Piedmont Ralph L.
Published: April 2006

ABSTRACT Both the California Psychological Inventory (CPI; Gough, 1987) and the five‐factor model of personality have roots in folk concepts of personality. The present article offers a conceptual analysis of CPI scales in terms of the five‐factor model. In the first study, judges rated the item content of CPI scales in terms of the five factors. In the second, CPI scales were correlated with the factors as measured by the NEO Personality Inventory (NEO‐PI; Costa & McCrae, 1985b) in a sample of 348 men and women ages 19 to 92. Both studies showed meaningful links between CPI scales and four of the factors; Agreeableness appeared to be underrepresented in CPI scales. The utility of systematic rational item analysis in terms of the five factors and the evolving relation of folk concepts to psychological constructs are discussed.
The Factor Structure of the Personality Research Form: A Cross‐National Evaluation
Authors: Stumpf Heinrich
Published: April 2006

ABSTRACT The present research examined the generalizability of the factor structure of the Personality Research Form (PRF) across various populations. A common methodology was used for factoring 18 data bases from largely differing samples (including data from one Asian and two European countries). In accordance with previous research results, five factors were rotated in every case and compared with two target factor solutions. A mean congruence coefficient of .93 as well as similar proportions of variance explained by the factors in the various populations indicated a large amount of generalizability for that structure. An alternative but similar structure, which had been interpreted in terms of the so‐called “Big Five” factors of personality, proved to be only slightly less generalizable. It was concluded that the fairly abstract constructs of both PRF factor structures are useful for describing personality in the cultures under study, leaving room for the possibility of more subtle or specific differences between the populations.
Appraisals of Childbirth Experience and Newborn Characteristics: The Role of Hardiness and Affect
Authors: Priel Beatrice , Gonik Nilly , Rabinowitz Betty
Published: April 2006

ABSTRACT Prior research has suggested an overlap between hardiness and negative affect in the prediction of self‐reported health outcomes. A prospective study, investigating the relationships between hardiness and negative and positive affectivity in the prediction of postdelivery outcomes was conducted. Maternal appraisals of childbirth difficulty and success in coping with labor, maternal perceptions of the infant, and the amount of analgesic intake, as well as the objectively assessed difficulty of labor, were the outcome variables. Subjects were 73 pregnant women expecting their first baby. Hardiness and negative and positive trait affect were evaluated during the second trimester of pregnancy, while the dependent measures were assessed during labor and 48 hours after. Hardiness measured as an additive construct did not predict appraisals of the observed health event independent of negative affect. However, two hardiness subscales—commitment and challenge—and the interaction between challenge and control were found to predict outcomes independent of negative affectivity. The pattern of relationships between negative affect with both subjective and objective assessments of childbirth difficulty confirms previous research findings on symptom perception. Findings suggest an anxious cognitive style among nonhardy subjects and underscore the importance of the study of hardiness as an interactive construct.
The Heritability of Characteristics Associated with Dispositional Empathy
Authors: Davis Mark H. , Luce Carol , Kraus Stephen J.
Published: April 2006

ABSTRACT This investigation used data from Loehlin and Nichols's (1976) study of over 800 sets of twins to examine evidence for the heritability of three facets of empathy: empathic concern, personal distress, and perspective taking. Expert judges first identified sets of adjectives, included within Loehlin and Nichols's original data, which reflected each empathy construct; these items were then validated in an independent sample. Comparisons of the responses given to these items by identical and fraternal twins in the Loehlin and Nichols investigation revealed evidence of significant heritability for characteristics associated with the two affective facets of empathy—empathic concern and personal distress—but not for the nonaffective construct of perspective taking. This pattern is consistent with the view that temperamental emotionality may underlie the heritability of affective empathy.
Detecting Anxiety and Defensiveness from Visual and Auditory Cues
Authors: Harrigan Jinni A. , Harrigan Kelly M. , Sale Beverly A. , Rosenthal Robert
Published: April 2006

ABSTRACT Defensive individuals have been shown to differ from non‐defensive individuals on a number of physiological and behavioral measures. We report two studies on observers' inferences of defensiveness, and the contribution of communication channels in the inference of defensiveness. Observers judged high and low state anxious segments of high and low trait anxious defensive and nondefensive individuals. Accurate assessments were made of (a) defensiveness, (b) state anxiety, and (c) trait anxiety: Individuals with higher levels of each variable were perceived as more anxious compared with the lower level. Effects for defensiveness and state anxiety were greater in audio‐only segments, while effects for trait anxiety were greater in video‐only segments. Inferences of defensiveness were greater at higher levels of state anxiety and trait anxiety. Low trait anxious defensive individuals were perceived as more anxious than the true low trait anxious. Results for defensiveness and trait anxiety were replicated in Study 2, and observers' perceptions of state anxiety matched individuals' self‐reports: Defensive individuals with maximal differences between high and low state anxiety were seen as more anxious in high state anxiety, while defensive individuals with minimal differences between high and low state anxiety were regarded as less anxious in high state anxiety.
Wishes, Gender, Personality, and Well‐Being
Authors: King Laura A. , Broyles Sheri J.
Published: April 2006

ABSTRACT Study participants (175 men, 230 women) made three wishes and completed measures of the five‐factor model of personality, optimism, life satisfaction, and depression. Common wishes were for achievement, affiliation, intimacy, and power as well as for happiness and money. T tests showed women were more likely to wish for improved appearance, happiness, and health; men were more likely to make power wishes and wishes for sex. Among participants who were highly involved in the wishing process, Extra‐version was related to making more interpersonal wishes and wishes for positive affect. Neuroticism was related to wishes for emotional stability. Agreeableness and Openness to Experience related to wishes reflective of these traits. Conscientiousness was related to low impulsivity. Depression was related to making highly idiosyncratic, specific wishes, suggesting the use of wishful thinking as a coping mechanism. In addition, happy participants were more likely to rate their wishes as likely to come true. Results indicate that the relatively commonplace process of wishing relates to traits, gender, and well‐being.
Children's perceptions of others' understanding of moral transgressions: who should know better and why
Authors: Buzzelli Cary A.
Published: April 2006

The present study examined children's perceptions of other children's ability to make moral judgements. Preschool, kindergarten, first‐ and second‐grade children rated the permissibility of moral transgressions for a same‐age peer, a younger child and an older child. Children also were asked why the transgressions were wrong. Preschool and kindergarten children rated transgressions equally wrong for a same‐age peer, a younger and an older child, whereas first and second graders rated transgressions for a same‐age peer and an older child as more wrong than for a younger child. Preschoolers stated they did not know why the transgressions were wrong for a younger child, while kindergarten children reasoned that a younger child did not know the rules. First and second graders reasoned that a same‐age peer and an older child should know ‘better’, but a younger child would not know ‘better’. Results suggest that children's perceptions of others' moral knowledge is related to children's ability to coordinate domains of social knowledge when making judgements of others' moral transgressions.
Can young children benefit from collaborative problem solving? Tracing the effects of partner competence and feedback
Authors: Tudge Jonathan , Winterhoff Paul
Published: April 2006

This research was designed to ascertain the extent to which and the conditions under which 5‐ to 6‐year‐olds benefit from collaborative problem‐solving. We were interested in the impact of (a) repeated collaborative sessions, with the problem difficulty tied to the current independent ability of the target children; (b) working with a more competent partner, an equally competent partner, or with no partner; and (c) immediate feedback from the materials. The data (obtained from a sample of 81 children) revealed that collaboration with a more competent partner was more beneficial than working alone or working with an equally competent partner, but only when feedback was not provided. With feedback, singletons improved more than those who worked with a partner, irrespective of the partner's relative competence. No benefits were found for repeated collaborative sessions; improvement occurred early and then levelled off. The results are set in the context of Piagetian and Vygotskian theory, and serve to illustrate that with regard to peer collaboration these theoretical positions are complementary rather than in opposition.
Influences on the effectiveness of peer interaction: children's level of cognitive development and the relative ability of partners
Authors: Messer David J. , Joiner Richard , Loveridge Nerys , Light Paul , Littleton Karen
Published: April 2006

Studies of peer interaction among children have generally shown that this experience aids performance, or at the very least does not result in poorer performance in relation to control conditions. Furthermore, working with a more able partner has been found to be a particularly effective form of peer interaction. In contrast, a model proposed by Karmiloff‐Smith suggests that at certain phases of cognitive development children may ignore feedback and information from task activities. These two ideas were tested in a study where pairs of 6–7 year old children had to balance a beam on a fulcrum during a computer task. The performance on a post‐test did not support either viewpoint. Children who were working with a more able partner were found to perform significantly worse than other children. The findings of a second study suggested that this effect may have been due to the more able children having an incomplete understanding of the computer task and they may have dominated social interaction thereby restricting the progress of the less able pupil. The findings from these two studies indicate that peer interaction can result in poorer learning outcomes, and that Karmiloff‐Smith's model should include the possibility of peer interaction effects.
Patterns of development in early empathic behavior: Environmental and child constitutional influences
Authors: Robinson JoAnn L.
Published: April 2006

The second year of life is a period of developmental change and instability in empathic expressions. In this study, we identify specific developmental patterns of global empathy during the second year and investigate maternal style, family environment, and temperamental factors as moderator influences on these patterns of development. The sample consists of 158 children selected from twin pairs whose empathic development had been previously studied at 14 and 20 months of age. Planned comparisons within specific groups (initially high, mid‐range, or low empathy) tested the difference between children who changed versus those who remained stable. Maternal style, family climate, and child temperament variables significantly differentiated children among different patterns of development. Child gender was an additional moderator of family influences on development among those children whose empathic responses were initially low. These findings suggest the importance of distinguishing patterns of development based on where in the range of behaviors development is tracked.
Adolescents' disclosure to best and good friends: The effects of gender and topic intimacy
Authors: Dolgin Kim G. , Kim Stephanie
Published: April 2006

The disclosure of 227 7th‐ through 12th‐grade adolescents to four other persons – their closest same‐ and cross‐sex best friends, and lesser‐but‐good same‐ and cross‐sex friends – about 40 topics varying widely in intimacy was examined; in addition, each subject rated every topic's intimacy. A (2) gender × (2) friend's gender × (2) closeness × (3) age × (3) intimacy level ANOVA yielded two large main effects (partial ω2 > .15), closeness and topic intimacy. Three large interaction effects – gender by friend's gender, friend's gender by intimacy, and gender by closeness by intimacy – were also found, as was a moderate‐sized closeness by gender by friend's gender interaction (partial co2= .08). A number of other effects were statistically significant but of only small magnitude. The perceived intimacy of 6 of the studied topics varied across age groups, and one topic, “your weight” was rated differently by males and females. The data are discussed in relation to previous research on adolescent gender differences in friendship and disclosure.
Children and their child care caregivers: profiles of relationships
Authors: Howes Carollee , Smith Ellen W.
Published: April 2006

One thousand three hundred and seventy‐nine (682 girls) caregiver‐child relationships were used to derive attachment behavior profiles. All of the children were enrolled in child care (72% in child care centers). Profile analysis was completed using five subscales of Attachment Q‐Set items. Three profiles were replicated on randomly drawn subsamples, on center based and in‐home based subsamples and on separate subsamples of toddler and preschool children. These profiles were labeled: difficult, avoiding and secure. Children in the secure profile had higher security scores than children in the difficult or avoiding profiles. Children in the avoiding profile appeared the most heterogeneous in attachment security. Children in the avoiding profile with high as opposed to low security scores were older and more likely to use the caregiver as a secure base, seek her for comfort and engage in positive negotiations. Observations conducted on the children with their caregivers provided external validity for the profiles. Children in the secure profile had the most adult involvement.
Social Networks Among Incarcerated Juvenile Offenders*
Authors: Clarke‐McLean Janet G.
Published: April 2006

This study examines the social networks and deviant behavior of 92 male and female adolescent offenders in a secure training school. Semi‐structured interviews were conducted individually with the youth and repeated following a four‐week interval. Record data were reviewed to assess behavioral adjustment. The Social Cognitive Map analytic technique was utilized to identify social clusters. Findings indicate that these extremely delinquent youth formed reasonably stable social networks within the institution. Social clusters were distinguished most strongly on the basis of gender, race and proximity. Individuals within clusters had similar levels of behavioral adjustment and perceptions of intimacy with peers. The processes of peer group formation are similar to those found among public school counterparts. Treatment implications are discussed.
The Role of the Group in Peer Group Entry
Authors: Zarbatany Lynne , Pepper Susan
Published: April 2006

This study explored psychological conditions affecting children's receptiveness to a newcomer (the guest) in a peer group entry task. Subjects were 93 host dyads (48 male) of 7‐ to 9‐year‐old children. Hosts played a word‐naming game for 5 min before being joined by a male or female guest. The hosts' pre‐entry interaction was coded to reflect an orientation toward the game (agentic) or toward each other and toward experimental setting demands (communal). Hosts' psychological orientation predicted entry outcomes. Specifically, hosts of excluded children verbally competed with each other (an aspect of agency) more than hosts of children who entered. Male hosts competed more than female hosts and female hosts helped and encouraged each other (aspects of the communal orientation) more than male hosts. These findings suggest that the strategies and effort required by children to achieve group entry may depend on prior psychological conditions attending the interaction of the peer group.
Sex differences in body composition, performance and behaviour in the Colombian rainbow boa (Epicrates cenchria maurus, Boidae)
Authors: Lourdais O. , Shine R. , Bonnet X. , Brischoux F.
Published: May 2006

Although most analyses of sexual dimorphism focus on overall body size (sexual size dimorphism), males and females of the same species may differ profoundly in their morphology, performance and behaviour even if the two sexes attain similar adult sizes. Thus, similarity in size may mask major sex‐based divergences in traits such as musculature and fat stores. Although female Colombian rainbow boas Epicrates cenchria maurus are slightly longer than males, we show that males are more muscular than females and, accordingly, males outperform same‐sized females in tests of strength. Musculature may enhance success in male–male combat. The two sexes also differ in body shape: the wider abdomens of females may allow more space to store fat and/or embryos. Lastly, male boas reacted more overtly to handling (via defecation and striking) than did females. These sex differences in morphology, performance and behaviour plausibly reflect ecological differences between the sexes in the wild, with males under sexual selection for increased physical strength and females under fecundity selection for enhanced reproductive output.
COATED VESICLES IN THE CYTOPLASM OF THE HOST CELLS IN OPHRYS LUTEA CAV. MYCORRHIZAS (ORCHIDACEAE)
Authors: BARROSO J. , PAIS M. SALOMÉ S.
Published: April 2006

Summary

The host cells from endomycorrhizas of Ophrys lutea Cav. contain many coated vesicles associated with dictyosomes, with a membrane system (probably partially coated reticulum) and with the host's sequestration plasmalemma. The contents of coated vesicles stain with neither the PATAg test for polysaccharides nor with ruthenium red.

The involvement of coated vesicles in the host/endophyte interactions during the establishment of O. lutea endomycorrhizas is discussed.
GROWTH AND NUTRIENT ACCUMULATION BY FRUITS OF THE PERENNIAL LEGUME, HARDENBERGIA VIOL ACE A, WITH SPECIAL REFERENCE TO MYRMECOCHORY
Authors: HOCKING P. J. , KORTT A. A.
Published: April 2006

Summary

The growth and mineral nutrition of developing fruits of the perennial Australian legume Hardenbergia violacea (Schneev.) Steam (Fabaceae) was studied using plants from a natural habitat near Rankins Springs, central‐western New South Wales, Australia. The accumulation and partitioning of dry matter and 12 mineral nutrients in pods and seeds of fruits is described. Seeds accumulated about 50% of the dry matter of a mature fruit, over 90% of its N and P content, 50 to 75% of its K, Ca, Mn, Cl, S, Zn, Cu and Mg, but less than 50% of its Fe and Na. Over 75 % of the N and P content of pods was redistributed during senescence, although other nutrients and dry matter were not redistributed to the same extent; there was negligible redistribution of Ca, Cl, Na, Fe and Mn from the pod. Redistribution of N and P from the pod could have provided up to 30% of these nutrients accumulated by mature seeds. Concentrations of most nutrients were higher in seeds than pods. The testa made up 60% of the dry matter content of a seed and contained the major proportion of its Ca, Mg, Cl, Na and Mn; the embryo contained most of the seed's contents of N, P, K, S, Zn and Cu.

The elaiosomes had less than 5% of the seed's dry matter and mineral nutrient content. The oil content of the elaiosome was 34%, compared to 12% for the embryo. Oleic acid made up over 60% of the fatty acid content of elaiosome oil. Aspartic acid, arginine and glycine were the major amino acids in the elaiosome. The embryo contained 10% of the non‐protein anti‐metabolic amino acid, canavanine, the elaiosome only 1%. Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis showed that the subunit protein compositions of the elaiosome and embryo were different. The composition of the elaiosome is discussed in relation to the nutrition of ants. It is concluded that, in H. violacea, the elaiosome represents a nutritionally cheap means to the plant of achieving secondary seed dispersal by ants.
LOCALIZED INCREASE IN NODULE ACTIVITY BUT NO COMPETITIVE INTERACTION OF COWPEA RHIZOBIA DUE TO PRE‐ESTABLISHMENT OF VESICULAR‐ARBUSCULAR MYCORRHIZA
Authors: AMES ROBERT N. , BETHLENFALVAY GABOR J.
Published: April 2006

Cowpea [Vigna unguiculata (L.) Walp.] plants were grown in a split‐root system using a calcined montmorillonite clay (Turface) as the growth medium. At transplanting, either the vesicular‐arbuscular mycorrhizal (VAM) fungus Glomus macrocarpum Tul. & Tul. and 100 mg hydroxyapatite (HAP) or 100, 200 or 400 mg HAP kg−1 without the VAM fungus were mixed into side 1 of the split‐root system. Side 2 received only 100 mg HAP kg−1. After 30 d, a combined inoculum of four Rhizobium isolates (TAL169, TAL173, TAL658 and IRC256) was applied to the surface of all pots. At harvest (60 d), root systems were separated from shoots, and nodule activity (acetylene reduction), plant dry weight, nitrogen (N) and phosphate (P) content and the percentage of VAM colonization were determined. There was no significant effect of treatment on either the N or P content of leaves or roots. The VAM fungus, however, significantly (P < 0.01) increased shoot dry weight. Root dry weight and nodule activity were significantly increased only on the VAM side of the split‐root system. Rhizobia from 30 nodules per half‐root system were identified using fluorescent antibody techniques. Strain TAL 173 was detected from 95% of the nodules and neither the VAM fungus nor P application affected competitive interaction by rhizobia for nodulation sites. Our work suggests the existence of a localized, non‐systemic, non‐P‐mediated influence of a VAM fungus on root dry weight and nodule activity in cowpea.
MORPHOGENETIC RESPONSE OF VEGETATIVE BUD EXPLANTS OF ADOLESCENT AND MATURE PICEA GLAUCA (MOENCH) VOSS IN VITRO*
Authors: DUNSTAN DAVID I. , MOHAMMED GINA H. , THORPE TREVOR A.
Published: April 2006

The formation of adventitious shoot primordia on cultured explants from vegetative buds of Picea glauca (Moench) Voss varied with the source tree. The best response, i.e. the highest number of responsive explants (10/25) and of shoot primordia per responsive explant (average 8.1), was found with buds excised from a tree in a natural stand (15 to 18 years old). However, explants from only one other tree of eight natural stand trees responded with shoot primordium formation. By comparison, explants from four out of five orchard trees (scions 25 to 28 years old) produced shoot primordia in vitro.

Of the material compared, the explants which were most likely to show shoot primordium formation were from the terminal bud and the nearest lateral buds of a main lateral branch. Explants from similar buds on subdominant branches of highest hierarchy are also included in this category. Finally, the original size did not significantly influence the number of shoot primordia produced on responsive explants 12 weeks after explantation.
SPOROCARPS OF AZOLLA MEXICAN A PRESL I. ISOLATION AND PURIFICATION OF MEGASPOROCARPS AND MICROSPORANGIA*
Authors: TOIA R. E. , BUZBY K. M. , PEPTERS G. A.
Published: April 2006

Azolla mexicana Presl, a heterosporous aquatic fern, consistently sporulates under routine culture conditions, producing both megasporocarps and microsporocarps in abundance. As a prelude to studies on germ plasm preservation, gametogenesis, embryogenesis, and efforts to establish interspecific hybrids, methods were developed to isolate and separate the reproductive structures. Fertile sporophytes were agitated to release the sporocarps. During this process mature microsporocarps ruptured to release microsporangia. A series of stainless steel sieves, ranging from 1130 to 200 μm in pore size, was used to separate megasporocarps and microsporangia from sporophyte debris and immature microsporocarps. Purified preparations of megasporocarps and microsporangia were obtained using sorbitol step gradients.
FLANDRIAN ENVIRONMENTAL HISTORY OF THE ISLE OF MULL, SCOTLAND
Authors: WALKEER M. J. C. , LOWE J. J.
Published: April 2006

Pollen percentage and pollen concentration data are described from an infilled basin within a Loch Lomond Stadial end moraine at Gribun on the west coast of the Isle of Mull, Inner Hebrides, Scotland. The pollen profile, which is over 13 m deep, spans most of the Flandrian stage and constitutes one of the most detailed records of post–glacial vegetational change for any area in northern Britain. Nine local pollen assemblage zones and five pollen concentration zones are identified in the pollen diagrams, and these can be correlated with biozones recognized in other profiles on Mull. In general, the data from Gribun confirm the spatial and temporal patterns of Flandrian vegetational developments that have been suggested by these earlier studies. However, the high level of biostratigraphic resolution within the Gribun profile places these palaeobotanical and associated reconstructions on a more secure footing, and it is therefore proposed that Gribun be considered as the type site for the Flandrian stage in this area of western Scotland.
THE ANATOMICAL CHARACTERISTICS OF ROOTS AND PLANT RESPONSE TO SOIL FLOODING
Authors: JUSTIN S. H. F. W. , ARMSTRONG W.
Published: April 2006

Ninety‐one plant species from wetland (WL), intermediate (INT) and non‐wetland (NWL) habitats were grown in flooded and drained soils and responses to flooding were assessed in relation to root anatomy and fractional root porosity (FRP).

Flooding response and tolerance were related to FRP. Rooting depth increased with FRP in accordance with diffusion model predictions and emphasized the ventilating efficiency of aerenchyma. Major determinants of FRP were cortical cell configurations, closeness of cell packing, the relative proportions of configuration types, porous: non‐porous tissue ratios, aerenchyma development and the type and degree of secondary growth. A classification of cortical types based on cell and aerenchyma patterns is presented.

Aerenchyma, both schizogenous and lysigenous, developed preferentially where pre‐aerenchymatous cortical cell configurations (in TS) were radial and particularly, cubic and radial typical of WL and INT species. Aerenchyma rarely formed from hexagonal non‐radial arrays which occur chiefly in NWL and in the outer cortical zones of WL and INT plants. The ventilating potential in non‐aerenchymatous tissue was shown to be greater for cubic (fractional porosity, FP, max. 0–2146) than for hexagonal arrays (FP max. 0˙0931); closer packing greatly accentuated the differences. It is suggested that cubic: hexagonal zonal ratios in roots may reflect a balance between respiratory and mechanical needs.

In a majority of WL and INT species, shoot weights were unaffected by or increased with flooding and maximum rooting depths usually much exceeded 50 mm. Cubic packing raised the FRPs, as did aerenchyma which was often much greater under flooding. In the dicotyledonous species, a suppression of secondary growth in some, and a highly porous phelloderm in others, helped maintain high FRP. A minority of species were anatomically and responsively similar to NWL plants; survival under flooding was attributed to shallow rooting.

Under flooding, the FRP of almost all NWL species was < 0˙055 due to hexagonal packing, a lack of aerenchyma and, in dicotyledonous plants, secondary growth with scanty phelloderm. Shoot weights were reduced in 50% of cases, rooting depths were <50 mm, and some species died. Some species were exceptional in having cubic and radial packings; a lack of aerenchyma was associated with continuing meristematic activity in the primary cortex.
THE ECTOMYCORRHIZAL INFECTION ZONE AND ITS RELATION TO ACID POLYSACCHARIDES OF CORTICAL CELL WALLS
Authors: NYLUND JAN‐ERIK
Published: April 2006

Cortical cell walls of spruce [Picea abies (L.) Karst.] and pine (Pinus sylvestris L.) were found to contain large amounts of acid polysaccharide, which was absent from all other cell walls studied. In its staining characteristics, calcium content, extractability and structure it was similar to the pectic substance filling intercellular regions in the cortex, xylem and other tissues. The acid polysaccharide also formed a matrix embedding fungal cells of the Hartig net in mycorrhizal roots. Matrix substance in the mantle was of a different character.

The distal limit of the acid polysaccharide wall incrustation marked the transition between the differentiation zone of the root tip and the mature cortex, and coincided exactly with the distal limit of the Hartig net and fungal penetration. The endodermis and, where present, the metacutis formed other barriers. Proximally, the onset of senescence and death of cortical cells made mycorrhiza formation impossible, or terminated the existing symbiotic relationship.

Thus, ‘the mycorrhizal infection zone’, i.e. the part of the root where fungal colonization could take place, was defined by (a) a particular wall composition and (b) a physiological condition. Such limitation is consistent with the theory of mechanical fungal penetration during mycorrhiza formation‐the pectins increase the cell‐wall flexibility‐as well as the model for host‐mycobiont interaction proposed in an earlier study (Nylund & Unestam, 1982).
ZINC TOLERANCE IN BETULA SPP.
Authors: DENNY HILARY J. , WILKINS D. A.
Published: April 2006

Clones of Betula pendula Roth, and B. pubescens Ehrh., collected as seed from zinc‐contaminated mine tailings, were grown aseptically in a liquid/perlite medium. Three zinc‐tolerant and four non‐tolerant genotypes were compared with respect to extension growth and zinc uptake over a range of external concentrations of zinc. The effect of increasing zinc concentration on total root length and root cell length was also examined. Extension growth declined rectilinearly as the external zinc concentration increased, but the relationship between uptake and external concentration was not rectilinear. After an initial proportional increase, concentrations of zinc in tissues remained constant over much of the range of external concentrations at which some growth was possible. Fresh weight concentrations of zinc in tolerant and non‐tolerant genotypes were similar at similar external concentrations. However, at a characteristic threshold external concentration, control of uptake broke down and plants were inundated with zinc. The decrease in extension growth was found to be due mainly to a progressive inhibition of cell elongation. Zinc tolerance in Betula lies in an ability to maintain proportionally more extension growth at similar internal and external zinc concentrations. Neither a tolerance mechanism involving internal detoxification, nor binding of zinc ions to electronegative sites in the cell walls, are consistent with the results. However, these findings are compatible with a tolerance mechanism involving control of uptake operating at the endodermis.