Birth order and a two-dimensional assessment of personality.

Higher order personality dimensions of extraversion-introversion and neuroticism were studied as functions of birth order in two-sib families, using 141 female subjects, with control over sex of sibling and sib age separation. No significant personality dimension variance was attributable to birth order in females. The results were considered briefly in terms of the importance of birth order, heritability questions, and the possible contribution of birth order to lower order traits.     

Birth order and selected work-related personality variables

A possible link between birth order and various individual characteristics (e. g., intelligence, potential eminence, need for achievement, sociability) has been suggested by personality theorists such as Adler for over a century. The present study examines whether birth order is associated with selected personality variables that may be related to various work outcomes. 3 of 7 hypotheses were supported and the effect sizes for these were small. Firstborns scored significantly higher than later borns on measures of dominance, good impression, and achievement via conformity. No differences between firstborns and later borns were found in managerial potential, work orientation, achievement via independence, and sociability. The study's sample consisted of 835 public, government, and industrial accountants responding to a national US survey of accounting professionals. The nature of the sample may have been partially responsible for the results obtained. Its homogeneity may have caused any birth order effects to wash out. It can be argued that successful membership in the accountancy profession requires internalization of a set of prescribed rules and standards. It may be that accountants as a group are locked in to a behavioral framework. Any differentiation would result from spurious interpersonal differences, not from predictable birth-order related characteristics. A final interpretation is that birth order effects are nonexistent or statistical artifacts. Given the present data and particularistic sample, however, the authors have insufficient information from which to draw such a conclusion.     

Birth order, family structure and personality variables

The birth order and family structure variables assessed included first or only child, position in multi-child family, position in dyadic family, age of parents at birth of given child, whether reared by one or both parents, whether reared under permissive or authoritarian family atmosphere. The personality variables assessed included Sociability, Anxiety, Dominance, Superego, Phlegmatic Temperament, Involvement, Self-Regard and other scales measured by the Howarth Personality Questionnaire. One hundred seventy female and 142 male undergraduates were tested. Significant relationships found included: anxiety lower in firstborns; superego higher in firstborns; persistence higher in those not dominated by elder sibling; phlegmatic temperament higher in permissive families; involvement and phlegmatic temperament lower in single parent families; self-pride higher in the elder of a sibling pair; individual tolerance higher in children reared by both rather than single parent.     

Birth order has no effect on intelligence: a reply and extension of previous findings

We address points raised by Zajonc and Sulloway, who reject findings showing that birth order has no effect on intelligence. Many objections to findings of null birth-order results seem to stem from a misunderstanding of the difference between study designs where birth order is confounded with true causal influences on intelligence across families and designs that control for some of these influences. We discuss some of the consequences of not appreciating the nature of this difference. When between-family confounds are controlled using appropriate study designs and techniques such as multilevel modeling, birth order is shown not to influence intelligence. We conclude with an empirical investigation of the replicability and generalizability of this approach.     

Birth order differences in normal personality traits: Perspectives from within and outside the family

The hypotheses of Sulloway (1996) regarding birth order differences in five-factor model personality traits were tested in a sample of 231 college students with the NEO Five-Factor Inventory (NEO-FFI; Costa & McCrae, 1992). Data were collected from three sources (self, peer, and parent) to systematically evaluate previous observations that birth order differences are more commonly found when ratings are obtained from family members than from observers outside the family (Ernst & Angst, 1983). Using a between-family design, students were selected only from families with two or three full biological siblings and no half-siblings, step-siblings, or adopted siblings. Firstborn (n = 103) and laterborn (n = 128) students were compared using NEO-FFI ratings by the self, by a same-sex college peer, and by a biological parent. No birth order differences were found for any of the five NEO-FFI scores using any of the three rating sources. Effect sizes (Cohen’s d) were less than .20 for all comparisons. Suggestions for new approaches to the study of birth order differences are considered, including the use of within-family designs and more contextualized personality variables.     

Some findings on prospect and refuge theory: II

This article presents four new studies on the efficacy of predictions based on prospect and refuge theory and summarizes the results over eight studies. New data covered 49 participants and 36 environments. The eight studies included in the summary covered 144 participants and 80 widely diverse environments (Japanese Tatami rooms, Western rooms, porch, meadow, neighborhood commercial, shopping mall, vacation landscapes). Data were available for hypotheses about five factors: prospect, refuge, light, venue, and spatial transition. Efficacy was represented by correlations for the levels of the factors with responses of preference or comfort. Overall, venue was the most efficacious factor (r = .42, 95% CI = .14, .64). Efficacies for the other factors were very near zero. It is suggested that a considerable amount of additional formal inquiry be conducted before assuming the utility of prospect and refuge theory.     

An empirical test of the astrological theory of personality

The present study investigated the accuracy of genethliacal horoscopes by asking each of the 15 Ss and a member of her family or a close friend—the nominee—to try to identify which one of 5 cast horoscopes pertained to the S, i.e. was based on her birth data. In addition, each S was rated on 5 personality dimensions by the astrologer who cast the horoscopes, the S herself and her nominee. Finally, the S completed the South African Personality Questionnaire which measured the dimensions psychometrically. Neither the Ss nor the nominees were able correctly to identify the S's horoscope. Regarding the 5 personality dimensions, it was found that the astrologer's ratings did not correlate with the psychometrically-obtained scores, the S's self-ratings or the ratings of the S by the nominee. There was, however, a reasonably high degree of consensus between the psychometrically-obtained scores, the self-ratings and the ratings of the nominees.     

Some empirical evidence for ecological dissonance theory

Using Festinger's cognitive dissonance theory as a model, the extension to Barker's ecological theory, referred to as ecological dissonance theory, was developed. Designed to examine the motivational dynamics involved when environmental systems are in conflict with each other or with cognitive systems, ecological dissonance theory yielded five propositions which were tested in 10 studies. This summary of the studies suggests operationally defined measures of ecological dissonance may correlate with workers' satisfaction with their jobs, involvement with their jobs, alienation from their work, and to a lesser extent, workers' conflict resolution behavior and communication style.     

Birth order and introversion-extraversion

The relationship between birth order and introversion-extraversion was investigated. Subjects were 70 male and 77 female undergraduates, all from three-child families. The measure of introversion employed was the Social Introversion Scale (Scale 0) of the Minnesota Multiphasic Personality Inventory. A two-way analysis of variance indicated that first borns were more introverted than either middle-horns or last-horns, with no difference between the latter two groups. It was suggested that inconsistent results in this area may be due to the use of different measures of introversion.     

Birth order of past presidents and Schlesinger's history cycles: support for Stewart's leadership theory

Stewart's hypothesis (1992) that adults who were only-children and first-born children are most suited to lead communities in more turbulent times while adults who were later-born children are most suited to lead in more tranquil times was tested by relating the male birth order of elected presidents to Schlesinger's 1986 public purpose and private interest periods. Consistent with Stewart's hypothesis, candidates who were only-children and first-born children tended to win during public purpose phases, which are characterized by the turbulence of greater political commitment, idealism, and broad social change.     

Drug tolerance and personality: Some implications for Eysenck's theory

Two previous studies, one of nitrous oxide and the other of amylobarbitone sodium, had shown that tolerance of these drugs, assessed by the ‘sedation threshold’ procedure, was influenced by an interaction between introversion-extraversion and neuroticism: tolerance was negatively correlated with E in High N subjects and positively with E in low N subjects. In a study described in the first part of this paper the same result was found for thiopentone among a group of 50 surgical patients, tested as part of their routine pre-operative procedure. The remainder of the paper is devoted to a more detailed analysis of this interactive effect, undertaken by combining the personality and sedation threshold scores from three studies. In this larger sample the previously observed results were broadly maintained, in that neurotic extraverts and normal introverts proved to have very low drug tolerance; the highest tolerance was found, however, in introverts with moderate, rather than very high, neuroticism. Comparison with similar data for a large group of neurotic patients revealed a somewhat different picture: the sedation thresholds of patients were sometimes predictable from their personality scores and sometimes from their diagnoses, the two not always coinciding. The results as a whole are discussed with reference to the possible neurophysiological mechanisms mediating depressant drug action and personality differences. Specifically it is suggested that some parts of the observed variation in drug tolerance might be explained by combining certain features of the modifications to Eysenck's theory of extraversion and neuroticism proposed, respectively, by Gray and by Claridge. However, it is considered that not all of the variation can be explained in this way and that other personality characteristics, probably those associated with ‘psychoticism’, are likely to prove important determinants of drug tolerance differences.