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A perspectivist approach is taken to the theory-construction process in psychological research. This approach assumes that all hypotheses and theories are true, as all are false, depending on the perspective from which they are viewed, and that the purpose of research is to discover which are the crucial perspectives. Perspectivism assumes also that both the a priori conceptual phase of research and the a posteriori empirical phase have both discovery and testing functions. Topics discussed include how the perspectivist approach can improve methodology training and practice (particularly as regards theory construction); what researchers accept as theoretical explanations; the nature of mediational theories; how theories can be formalized, expressed in multiple modalities and for various scaling cases; and how experimental designs can be enriched by theory-guided mediational and interactional variables.

Granulocyte macrophage-colony stimulating factor (GM-CSF) increases ovine interferon-tau (oIFNtau) secretion by ovine conceptuses, but endometrial production of GM-CSF has not been characterized. Endometrial GM-CSF expression was evaluated in ovariectomized ewes implanted with estradiol-17beta (E(2)) and/or progesterone (P(4)) for 14 days, in day 14 cyclic and day 14 pregnant ewes. Relative levels of endometrial GM-CSF mRNA were 3-fold higher in E(2)- and E(2)/P(4)-treated ewes than that of control or P(4)-treated ovariectomized ewes. Levels of endometrial GM-CSF mRNA for cyclic ewes were similar to E(2)- and E(2)/P(4)-treated ewes, but amounts of GM-CSF mRNA in pregnant ewes were 2-fold higher. GM-CSF concentrations in endometrial culture media, determined by GM-CSF bioassay, for cyclic and E(2)/P(4)-treated ovariectomized ewes were 3-fold higher than those of control, E(2)- and P(4)-treated ovariectomized ewes; however, amounts of GM-CSF in pregnant ewes were 2-fold higher. Immunoreactive GM-CSF, examined by western blot, was detected in the culture medium from E(2)/P(4)-treated ovariectomized, cyclic and pregnant ewes. Luminal and glandular epithelia and stromal regions were determined to be sites of GM-CSF expression by immunohistochemistry and in situ hybridization techniques. Data indicate that combined E(2) and P(4) treatment of ovariectomized ewes is sufficient to restore GM-CSF expression to the level found in cyclic ewes; however, GM-CSF mRNA and protein in pregnant ewes is 2-fold greater than in ovariectomized or cyclic ewes. These data suggest that the conceptus, in addition to steroids, may play a role in the regulation of endometrial production of GM-CSF.

Secretion into the uterine lumen follows a precise pattern during early pregnancy. Near the end of the second week of pregnancy and coincident with elongation of conceptuses, retinol, retinol binding protein (RBP), estradiol (E2), and prostaglandins E (PGE) and F (PGF) increase in the uterine lumen, and RBP mRNA increases in the endometrium. In the present studies the potential for E2 (0.1 microM) and retinol (10 microM) to regulate RBP and PG production by cultured luminal (LEC) and glandular (GEC) epithelial cells collected from postpubertal females and LEC from prepubertal gilts was examined. Endometrial tissue was collected surgically from cyclic and pregnant females (n = 8) on d 10 and 13 postestrus (first day of estrus = d 0) and from 120- and 150-d-old prepubertal gilts that were treated with progesterone (P4) (2.2 mg x kg(-1) x d(-1), n = 6) or corn oil (n = 6) for 14 d prior to tissue collection. The LEC from postpubertal females responded to retinol with increased (P < 0.05) RBP, PGE, and PGF in culture medium and increased (P < 0.07) RBP mRNA but E2 decreased (P < 0.05) RBP and RBP mRNA and had no effect on prostaglandins. No E2 or retinol effects on secretions of GEC occurred in vitro, but a day x pregnancy status interaction (P < 0.06) affected PGE output by the GEC. Secretion of PGE was greater when GEC were collected on d 10 of pregnancy than from d-10 cyclic or d-13 pregnant or cyclic females. Both E2 and retinol stimulated (P < 0.05) secretion of RBP by LEC isolated from prepubertal gilts, but their effects were not additive. In vivo treatment of prepubertal gilts with P4 increased (P < 0.05) RBP and decreased (P < 0.05) PG production by LEC in vitro. Therefore responses to E2 and retinol differ between pre- and post-pubertal females, and retinol may function in the regulation of endometrial RBP and PG secretion.

A study was conducted to determine the presence of cortisol in body tissue of porcine embryos at days 25 and 35 of gestation. Cortisol concentrations (ng/mg DNA) were low but measurable at day 25 and increased eightfold by day 35 during a time when body weight increased 6.4-fold. At day 35, there was a highly significant positive linear regression of body weight on cortisol concentrations. The source of this embryonic cortisol is not known, but its presence suggests the opportunity for cortisol to influence porcine embryonic development at these early gestational stages.

Studies were conducted to determine whether the corticosteroids cortisol and aldosterone, and corticosteroid-binding globulin (CBG) were present in the porcine early-embryonic environment. Cortisol was measured in uterine flushings from white crossbred gilts at Days 7, 10, 13, and 16 of the estrous cycle and pregnancy. Total content of cortisol increased (p < 0.01) between Days 13 and 16, and immunoreactive CBG (ir-CBG) increased (p < 0.01) between Days 10 and 13, in both cyclic and pregnant gilts. In a separate study with Chinese Meishan gilts, total cortisol and aldosterone content of uterine flushings increased (p < 0.02) between Days 10 and 15 of the estrous cycle and pregnancy. In another study with white crossbred gilts, CBG-like binding activity in uterine flushings was low at Day 10, then increased over 100-fold at Day 15 (p < 0.01). However, levels of CBG-like binding activity on Day 15 were 100-fold lower than those of ir-CBG measured in the previous study and could bind less than 4% of the uterine luminal cortisol. Differences between ir-CBG and CBG binding might be due to the ability of the CBG antibody to recognize either biologically inactive CBG or structurally similar molecules. CBG-like binding activity, which appeared unrelated to glucocorticoid receptors, was also present in the endometrial cytosol of white crossbred gilts. Concentrations (fmol/mg protein) of endometrial CBG-like activity decreased (p = 0.03) between Days 10 and 15 of the estrous cycle and pregnancy, did not differ with reproductive status, and on Day 15 were comparable to concentrations in uterine flushings but threefold lower (p < 0.01) than those in the serum. Equilibrium dissociation constants for CBG-like binding activities were comparable among the three locations. These studies indicate that corticosteroids are present-primarily in the free form-within the porcine uterine lumen and could influence early porcine conceptus development. Endometrial CBG-like binding activity could mediate actions of cortisol or progesterone on uterine function.

Interferon-tau (oIFNtau), the major secretory product of ovine conceptuses between days 13 and 21 (day 0=day of estrus) of pregnancy, is implicated in the process of maternal recognition of pregnancy. Culturing of day-14 and day-16 conceptus tissues in the presence of human granulocyte macrophage-colony stimulating factor (hGM-CSF) or interleukin-3 (IL-3) produces a marked increase in oIFNtau mRNA and protein expression. Since GM-CSF and IL-3 are localized at the luminal and glandular epithelia of the ovine endometrium, maternally derived GM-CSF and IL-3 may affect conceptus production of oIFNtau in a paracrine manner. However, the molecular mechanisms by which endometrial GM-CSF and IL-3 up-regulate oIFNtau production have not been defined. As an initial investigation of the signaling pathway regulating the GM-CSF induction of the oIFNtau gene, day-16 conceptuses were treated with an inducer, phorbol 12-myristate 13-acetate (PMA) and an inhibitor, calphostin C of the protein kinase C (PKC) pathway. Treatment with either 150 units/ml hGM-CSF (P<0.01) or 10 nM PMA (P<0.05) resulted in a significant increase in oIFNtau mRNA expression. Pretreatment of conceptuses with 1 microM PMA for 12 h to produce PKC-deficient tissues or treatment with 50 mM calphostin C abolished the hGM-CSF-induced increase in oIFNtau mRNA. An in vitro expression system was established for the analysis of oIFNtau gene regulatory sequences. The oIFNtau010 gene has been isolated previously and found to be the principal oIFNtau gene up-regulated during the preimplantation period. 5'-Flanking regions of the oIFNtau010 gene, 2 kb and 0.8 kb, were cloned into a basic chloramphenicol acetyltransferase reporter plasmid. These oIFNtau010 promoter constructs, along with expression controls, were transfected into human choriocarcinoma cells (JAR and JEG3) and their responsiveness to hGM-CSF and second messenger system activators including PMA, calcium ionophore (A23187) and 8-bromo-cAMP were characterized. The oIFNtau010 promoter constructs were up-regulated by hGM-CSF and PMA treatments (P<0.01). Combined treatment with PMA and A23187 prevented the promoter activation seen with PMA alone. The conceptus culture data, along with the results from the transfection experiments, suggest that the stimulatory effect of GM-CSF on oIFNtau is mediated through the PKC second messenger system.

To correct a common imbalance in methodology courses, focusing almost entirely on hypothesis-testing issues to the neglect of hypothesis-generating issues which are at least as important, 49 creative heuristics are described, divided into 5 categories and 14 subcategories. Each of these heuristics has often been used to generate hypotheses in psychological research, and each is teachable to students. The 49 heuristics range from common sense perceptiveness of the oddity of natural occurrences to use of sophisticated quantitative data analyses in ways that provoke new insights.

The association between uteroferrin (UF, measured as acid phosphatase [AP] activity), retinol-binding protein (RBP), and transferrin (TF), within the intrauterine environment during the estrous cycle and pregnancy was examined. Pregnant gilts were killed on Days 7, 10, 13, 16, 19, 25, 30, 40, 50, 60, 70, 80, and 90. Cyclic gilts were killed on Days 7, 10, 13, and 16. On Days 7 through 19, each uterine horn was flushed with 20 ml Minimum Essential Medium. On Days 25 through 90, serum and allantoic fluid samples were collected from each fetus within each gilt and pooled for each gilt. Uterine flushings, allantoic fluid, and fetal serum samples were assayed for AP, RBP, and TF. Endometrium was collected from all gilts and cultured with [3H]-leucine; conditioned medium was measured for nondialyzable radioactive macromolecules, AP, and RBP. In uterine flushings, AP, RBP, and TF were low on Day 7, and then increased markedly (p < 0.01) by Day 13 in both cyclic and pregnant gilts. After log transformation of the data, AP was highly correlated with RBP (r = 0.99) and TF (r = 0.91, p < 0.01). Secretion of RBP and AP by endometrium in culture also increased (p < 0.01) during this period and was similar in cyclic and pregnant gilts, and RBP and AP secretion were highly correlated (r = 0.65, p < 0.01). Endometrial tissue did not secrete detectable amounts of TF in culture. Concentrations of all three proteins were low in allantoic fluid on Day 25, after which time they increased to Day 40, and then either stabilized to Day 70 followed by a decrease to Day 90 (AP and TF) or decreased to Day 90 (RBP). Endometrial secretion of both AP and RBP increased between Day 25 and 30. Then, AP increased further to Day 40 and did not change to Day 60, while RBP did not change from Day 30 to Day 60. Both decreased from Day 60 to 70, did not change to Day 80, and then increased again to Day 90. The association of RBP and TF concentrations with AP in various maternal and conceptus compartments during pregnancy is consistent with the hypothesis that one function of these two proteins may be to protect maternal and fetal tissues from lipid peroxidation that is a possible consequence of iron transport via endometrial secretion of UF.

Insofar as people organize information about and evaluations of important topics in connected and coherent systems, attitudes may be changed from within by enhancing the salience of information already present virtually within the person's belief system without communicating new information from outside sources. A cognitive positivity bias is predicted such that stimulus evaluation (e.g., self-esteem) is affected more by characteristics that the stimulus possesses than by ones it lacks. Experiment 1 tested relations between participants' momentary self-esteem and concurrently salient desirable (vs. undesirable) self-characteristics possessed (vs. lacked). Experiments 2 and 3 changed participants' self-esteem by using directed-thinking tasks to manipulate the salience of desirable (vs. undesirable) self-characteristics possessed (and, to a lesser extent, lacked).

The effect of interleukin-3 (IL-3) on conceptus production of ovine interferon tau (olFNτ) was examined using two dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (2D SDS-PAGE), western blot, northern/slot blot,in situ hybridization and immunohistochemical methodologies. Ovine conceptuses (day 17,n=14) were culturedin vitro for 24 h in Eagle's Minimum Essential Medium (MEM) containing various doses of human recombinant interleukin-3 (hIL-3). At 75 and 150 colony forming units (units)/ml hIL-3, amounts of oIFNτ released into the culture media increased 3-8-fold over controls while at 300 units/ml (60 pM), hIL-3 did not enhance oIFNτ production. These variations in production of oIFNτ parallel amounts of oIFNτ mRNA detected by northern and slot blot analyses. Ovine IL-3 mRNA was primarily localized at luminal and glandular epithelia with minor staining at stromal regions of uterine endometria collected from day 17 pregnant ewes but its polypeptide was localized in the luminal epithelial region. However, such signals were not detected in day 17 conceptuses. Ovine IL-3 mRNA and its polypeptide were also localized at the same regions of the endometrium obtained from cyclic ewes on days 8 and 12. The effect of hIL-3 on the enhancement of oIFNτ productionin vitro could be mimicked by the addition of phorbol 12-myristate 13-acetate (PMA). The present observations demonstrate that the hemopoietic cytokine, IL-3, stimulates conceptus production of oIFNτin vitro and that ovine IL-3 and its mRNA are localized in the maternal endometrium. These results suggest that a cytokine, IL-3, produced by the maternal endometrium, is involved in conceptus production of oIFNτ which may result from the activation of a second messenger system, protein kinase C.

Experiment I was designed to determine the optimal dose of phorbol 12-myristate 13-acetate (PMA) that inhibited progesterone production when infused into the ovarian artery. The most efficacious dose of PMA was 2 mumol. Experiment II was designed to determine whether activation of protein kinase C (PKC) inhibited progesterone production without initiating luteolysis. Ewes received ovarian arterial infusions of 4 alpha-phorbol (2 mumol, n = 4), PMA (2 mumol, n = 8), or prostaglandin F2 alpha (PGF2 alpha; 1 mumol, n = 5). Concentrations of progesterone in serum decreased by 3 h in PMA-treated ewes and by 5 h in PGF2 alpha treated ewes (p < 0.05). By 48 h, serum levels of progesterone in PMA-treated ewes had returned to control values; but in PGF2 alpha-treated ewes they remained low for the duration of the experiment. Luteal weights and progesterone contents at 48 h were similar in 4 alpha-phorbol- and PMA-treated ewes but were decreased in PGF2 alpha-treated ewes (p < 0.05). Experiment III was designed to determine whether PGF2 alpha or PKC activation induced oligonucleosome formation or influenced mRNA levels for cytochrome P450sec or 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4 isomerase (3 beta-HSD). Ewes received treatments as in experiment II, and CL were collected at 3, 12, or 24 h (n = 3-4 per group). Luteal weights were decreased (p < 0.05) and oligonucleosome formation was increased (p < 0.05) in PGF2 alpha-treated ewes compared to controls or to PMA-treated ewes by 12 h.(ABSTRACT TRUNCATED AT 250 WORDS)

The objective of these experiments was to determine the pattern of mRNA expression for cytochrome P450 side-chain cleavage (P450scc) and 3 beta-hydroxysteroid dehydrogenase/delta 5,delta 4 isomerase (3 beta-HSD) during luteinization of the follicle and in ovine luteal tissue on Days 3, 6, 9, 12, and 15 of the estrous cycle. Mean concentration of mRNA for P450scc was not different in follicles collected 4 or 24 h after the onset of estrus but increased (p < 0.05) 3-fold by 48 h (corpus hemorrhagicum). With the methods used, mRNA for 3 beta-HSD was not detected until after ovulation and formation of the corpus hemorrhagicum (48 h after onset of estrus). In luteal tissue, mean concentration of mRNA for P450scc increased from Days 3 to 9 (p < 0.05) and had decreased (p < 0.05) by Day 15. Mean concentration of mRNA for P450scc was higher (p < 0.05) in small luteal cells on Day 9 than on Day 15, with values on Days 6 and 12 being intermediate. In large luteal cells, mean concentrations of P450scc mRNA increased (p < 0.05) between Days 6 and 12 and then decreased (p < 0.05) on Day 15. Mean concentration of mRNA for 3 beta-HSD was not different (p = 0.33) in luteal tissue on any day examined. In small luteal cells, mean concentrations of mRNA for 3 beta-HSD decreased between Days 6 and 15 (p < 0.05) while in large luteal cells, mean concentrations decreased (p < 0.05) between Days 12 and 15.(ABSTRACT TRUNCATED AT 250 WORDS)

A number of morphological and biochemical changes occur as the cells of the recently ovulated follicle luteinize and develop into a functional CL. There are two distinct steroidogenic luteal cell types that appear to differentiate from thecal and granulosal cells in the follicle. The control of progesterone secretion is quite different in the two cell types. Prostaglandin F2 alpha (PGF2 alpha) is the primary luteolytic hormone in most mammals. PGF2 alpha appears to exert its antisteroidogenic actions via activation of the protein kinase C system, while its cytotoxic effects appear to be mediated via a dramatic increase in intracellular levels of free calcium. The mechanisms involved in maternal recognition of pregnancy are very diverse between species and may involve direct luteotropic stimulation of the CL, reduced uterine secretion of PGF2 alpha, and/or inhibition of actions of PGF2 alpha at the level of the CL.

Educational campaigns against health-threatening behaviors such as drug abuse may lose effectiveness because they tend to be narrow, atheoretical and to stress negative effects. As a corrective, it is proposed that health campaigns take into account the broad range of human needs and consider how the health-threatening behavior may be gratifying to each need. This allows taking into consideration not just the bad effects (which tend to be obvious) of such behaviors as drug abuse, but also the gratifications they provide to a variety of human needs, by their associated lifestyles as well as by their pharmaceutical effects. In this way anti-drug campaigns can be made to cope more relevantly with the attractions of such health-threatening behaviors. We sketch 16 theorized human needs, widely contrasting in their assumption of what instigates human action and what terminates it, each of which theories has proven provocative in guiding basic research. From each of the 16 theories some implications are drawn regarding the attractions of drug abuse and regarding the design of educational campaigns against such health-threatening behaviors.

Eleven ovariectomized Hereford x Simmental cows and 10 ovariectomized crossbred heifers (primarily Angus and Hereford) were given the Syncro-Mate B (SMB) estrous synchronization treatment. The SMB treatment consisted of a 2 ml i.m. injection containing 5 mg of estradiol valerate and 3 mg of norgestomet plus a hydron ear implant containing 6 mg of norgestomet. The ear implant was removed 9 d later. Cows and heifers were considered in estrus only if they stood for mounting by a herdmate or a bull. Observations for estrus were made four or six times each day for 3 d after implant removal. The 21 animals were used in eight trials. Each trial involved 9 or 11 cows or 5 or 10 heifers. Four days to three weeks elapsed between implant removal and implant insertion for the next trial. No ovariectomized cow or heifer was observed in estrus for 21 d before treatment with SMB. In the eight trials, 3 of 9, 7 of 9 and 6 of 11 cows exhibited estrus, whereas 5 of 10, 1 of 5, 3 of 5, 3 of 5 and 5 of 5 heifers exhibited estrus after treatment. When data were pooled, 16 of 29 (55.2%) cows and 17 of 30 (56.7%) heifers exhibited estrus after treatment. Our data indicate that the SMB treatment can induce estrus in cows and heifers, independently of the ovaries.

Our research program focuses on thought systems consisting of a core event that might befall a person and other topics evoked in free associating on this event, mostly its salient antecedents and consequences. We theorize that the pattern of salient antecedents and consequences evoked by the core event are related to its judged desirability and likelihood by several adaptive principles, such that when a change is directly induced in one part of the belief system it produces predictable remote adjustments in other parts. In a first experiment we manipulated the core event's judged desirability or likelihood and tested for predicted remote effects on the salience of antecedents and consequences. A second experiment conversely manipulated the salience of antecedents or consequences and tested for predicted remote effects on the core event's judged desirability and likelihood.

A discrimination theory of selective perception was used to predict that a given trait would be spontaneously salient in a person's self-concept to the exten that this trait was distinctive for the person within her or his social groups. Sixth-grade students' general and physical spontaneous self-concepts were elicited in their classroom settings. The distinctiveness within the classroom of each student's characteristics on each of a variety of dimensions was determined, and it was found that in a majority of cases the dimension was significantly more salient in the spontaneous self-concepts of those students whose characteristic on thedimension was more distinctive. Also reported are incidental findings which include a description of the contents of spontaneous self-comcepts as well as determinants of their length and of the spontaneous mention of one's sex as part of one's self-concept.

Eleven 3-yr-old crossbred Angus cows that had raised one calf each were mastectomized at 6 to 7 mo of their second gestation. All calves were removed from cows within 12 h after birth. Cows were kept in a drylot with a fertile bull for 60 d after parturition. Cows were observed for estrus every 6 h, and blood serum was collected daily and assayed for progesterone. The average first ovulation and first estrus occurred at 13.9 and 20.1 d after parturition, respectively. Nine of 11 cows conceived, and the average time of conception was 34.3 d after parturition. The next year, eight of the same mastectomized cows were allocated to two equal groups. In one group, calves were removed from cows within 12 h after birth, whereas in the other group, calves remained with cows for 46 to 53 d. Calves that remained with their dams were hand fed from a bottle or bucket every 12 h. The two groups of cows were kept in separate drylots about 50 m apart, and a fertile bull was kept with each group. Blood samples were obtained from all cows, and they were observed for estrus as before. Cows withcut calves ovulated before 22 d (average 16.0), exhibited estrus by 33 d (average 24.0), and conceived by 40 d (average 30.5) after calving. None of the cows with calves ovulated or exhibited estrus earlier than 49 d after calving. However, all cows ovulated by 4 d (average 3), exhibited estrus by 10 d (average 5.5), and conceived by 11 d (average 9.3) after calf removal. We conclude that cow-calf interaction can suppress ovulation and estrus even when suckling and lactation do not take place.

Predicted differences in modes of thinking about self versus thinking about other people, derived from assumptions regarding one's privileged information about the self, were tested by comparing the types of verbs used in free descriptions of self versus the types of verbs used in free descriptions of other people. Three-minute responses to "Tell us about your family" and "Tell us about school" probes were divided into individual subject/verb/qualifier thought segments, from among which those with myself as subject versus those with other person(s) as subject were selected as the independent variable for testing six predicted self-other differences. It was found, as predicted, that the self more than other people is thought of concretely in terms of what one does (verbs of action) rather than abstractly in terms of what one is (verbs of state). Among state verbs, the self, more than others is described in terms of dynamic becoming rather than in terms of static being states; among action verbs, the self more than others is described as covertly reacting rather than as overtly acting. As regards overt actions, the self more than others is thought of as physically acting rather than as socially interacting; as regards covert reactions, the self more than others is thought of as having affective rather than cognitive reactions. Finally, the self more than others is described in terms of what one is not rather than what one is. The interaction effects on these six verb-ratio differences between self-conceptualizing versus other conceptualizing and age, gender, stimulus context, and response modality are described.

The distinctiveness postulate regarding selective perception implies that an aspect of a complex stimulus is likely to be noticed in direct proportion to its distinctiveness in the environment in which it is perceived. An implied prediction tested in the present study is that handedness is more salient in the self-concepts of left-handers than of right-handers. The spontaneous self-concept was measured in two different populations by open-ended "Tell us about yourself" questions. In each group, a significantly greater proportion of left- than right-handers mentioned their handedness as part of their self-concept.

It is assumed here that even as intimate and individualistic an experience as one's sense of self is affected by the social context in which the self-thoughts arise. As regards two major social worlds of childhood, family and school, it is postulated that the family's nurturent atmosphere fosters a more passive self-concept in contrast to a more dynamic sense of self promoted by the school's press toward achievement. Six predictions were derived that self-thoughts in the two contexts will differ in basic psycholinguistic characteristics, the types of verbs used to describe the self. To test these predictions children's three-minute descriptions of their family and of their school were content analysed into successive subject/verb/complement thought segments, from among which we selected out self-thoughts (segments with self as subject). An analysis of the types of verbs used in self-thoughts evoked by family versus school probes supported the six predicted differences in verb types derived from our postulate of a more passive self-concept in the family context. Specifically, in family more than in school contexts the self is perceived passively in terms of state rather than action verbs (of what one is rather than what one does); in terms of static states of being rather than dynamic states of becoming; in terms of overt actions rather than covert reactions; in terms of physical actions rather than social interactions; in terms of cold cognitions rather than hot affects; and in terms of simple affirmations rather than reflexive negations. These six manifestations of a more passive self in family than school social contexts are robust across age, gender and response modality.

How likely people are to think of themselves in terms of a given personal characteristic is predicted from the distinctiveness postulate that the person, when confronted by a complex stimulus (such as the self), selectively notices and encodes the stimulus in terms of what is most peculiar about it, since these peculiar characteristics are the most informative in distinguishing it from other stimuli. This partial view of the person as an information-encoding machine (one is conscious of oneself insofar as, and in the ways that, one is different) is used to derive four predictions implying that ethnic identity is salient in children's spontaneous self-concepts to the extent that their ethnic group is in the minority in their social milieu at school. Our measure of salience of ethnicity was its being spontaneously mentioned by the children in response to a nondirective "Tell us about yourself" question. All four predictions were confirmed, though for several of the findings there are plausible alternative explanations.