Only children in the 21st century: Personality differences between adults with and without siblings are very,very small

Negative beliefs about only children suggest that they are spoiled and unlikable, with these early personality differences persisting across the lifespan. Early research found little support for the idea, yet, negative views towards only children remain prevalent. The current research re-visited the issue using a large national panel study of New Zealand adults (N = 20,592) to assess mean differences in personality between those with and without siblings. Adults with no siblings reported significantly lower levels of conscientiousness and honesty-humility and higher levels of neuroticism and openness than adults with siblings; however, mean differences failed to reach the threshold of even a small effect size (|d’s| = 0.08–0.11). Beliefs about only children appear to contradict actual group differences.     

Conduct disorder and personality

A sample of children with a diagnosis of conduct disorder and a sample of children from a London comprehensive school were investigated. Three questionnaires were administered to assess personality, impulsiveness and anxiety. Of the personality measures contained within the Junior Eysenck Personality Questionnaire only Psychoticism was found to significantly differentiate the conduct disorder and normal control samples. The Impulsiveness scale of the I₆ also differentiated the two samples. There were no significant differences between the two samples in their scores on the anxiety scale of the “What I Think and Feel”. The findings are discussed in relation to theories of personality proposed by Eysenck and Eysenck (1969), Gray (1987) and Quay (1988).     

The relationship of extraversion,neuroticism, and sensation-seeking to questionnaire-derived measures of nervous system properties

Five obliquely rotated factor analyses were performed on items from Eysenck and Eysenck’s (1975) EPQ, Zuckerman’s (1975) Sensation-Seeking Scale, and Strelau’s (1972) temperament inventory (STI), administered to 277 subjects (Ss). The analyses were used to examine the relationships between the personality dimensions E, N, L, P and Sensation-Seeking, which pertain mainly to social situations, attitudes and feelings, and questionnaire-derived measures of nervous system properties, which, while validated on experimental indices of nervous system properties derived from Nebylitsyn’s (1972) model, are expressed as characteristic features of social behavior, work style and activity. Four factors were identified—extraversion/strength of excitation/mobility; self-control of affect/stability/caution; strength of inhibition/verbal control/motor expressiveness/ nonmanipulativeness; and sensation-seeking/nervousness. The results offer support for Eysenck’s claim of some identity between excitatory strength and E, for the reported relationship between E and mobility, and for Eysenck’s conditioning postulate. They also suggest that similar temperamental variables underlie individual differences in both social and occupational/motor activity. Since Strelau’s STI items are validated on experimental indices of nervous system properties, it follows that typological characteristics may be inferred from questionnaire data derived from both behavioral categories.     

The relationship between temperament and personality: An exploratory study

Although the terms temperament and personality are often used interchangeably in the literature and clearly are conceptually related, there is little empirical data to illuminate their relationship. In this exploratory study we measured temperament (using the Dimensions of Temperament Survey), and personality (using the Eysenck Personality Questionnaire), in young adolescents and in adults. Some age and sex differences in relationships between the measures and their correlations were found. The temperament dimension of adaptability was clearly related to Eysenck's Extraversion factor and reactivity to Neuroticism in females. More substantial relationships emerged in the adult sample than in the adolescent group, Our data, combined with that of a 1984 Australian study using different techniques, provides substantial support for measurable overlap between some dimensions of temperament derived largely from the developmental literature, and Eysenck's personality theory.     

Individual differences in anxiety and executive functioning: A multidimensional view

The relationship between individual differences in anxiety and executive functioning was investigated in a sample of young adults. Verbal and spatial working memory, resistance to interference, negative priming, and task‐switching measures were used to assess three executive functioning dimensions: updating, inhibition, and shifting. An additional index of basic psychomotor speed was added to this cognitive battery. According to the multidimensional interaction model of anxiety proposed by Endler (1997), state (cognitive–worry and autonomic–emotional) and trait (related to social evaluation, physical danger, ambiguous situations, and daily routines) anxiety were assessed in this evaluation context. Results indicated that shifting and inhibition (negative priming) efficiency were negatively related to state (cognitive–worry) and trait (related to social evaluation) anxiety. However, there was a relative advantage of subjects higher in social evaluation apprehensions in their memory updating performance. The results are consistent with several predictions of the attentional control theory (Eysenck, Derakshan, Santos, & Calvo, 2007), and are relevant for research regarding the interaction of situational, personality, and cognitive functioning dimensions.     

Prediction of coherence in adolescence: Gender differences in social skills, personality, and family climate

The gender differences for personality structure, family climate, and social skills among adolescents were investigated in relation to their sense of coherence. The sample consisted of 742 adolescents (371 males and 371 females). The instruments included the Sense of Coherence scale, and the Hebrew adaptations for the Social Skills Checklist, the Family Environment Scale, and the Junior Eysenck Personality Questionnaire. Significant differences were found between the two groups' perceptions of family climate: The male adolescents viewed their families as more encouraging of every aspect of personal growth within a more controlled family system. The female adolescents were found as having higher levels of social competence. Regarding personality structure, the males reported higher Psychoticism scores, and the girls higher Neuroticism, Extraversion, and Lie scores. No significant differences were found between genders on the sense of coherence scores, yet multiple regression analysis revealed that gender, Neuroticism, social skills, and two aspects of family climate (Relationship and Personal Growth) added significantly to the explanation of the variance, in addition to the interactions of gender with Relationship and Personal Growth, and of Neuroticism with Relationship, Extraversion, and Psychoticism. These results were discussed within the construct of sex-role differences.     

Eysenck's theory of personality and child-adult emotional attachments

The present study was mainly designed to examine the link between child-adult emotional bonds and personality characteristics. A sample of Pakistani adolescents aged between 13 and 14 completed the Emotional Attachment Scale and the Eysenck Junior Personality Questionnaire. Adult subjects to whom the adolescent subjects were predominantly emotionally attached were also asked to complete the Eysenck Adult Personality Questionnaire. The results indicated that children tend to develop emotional attachments to those parents whose personality scores correlate significantly positively with theirs; however, if they attach to nonparent adults, no significant association between their personality scores and those for adults exists.     

A quantitative review of the relations between the “Big 3” higher order personality dimensions and antisocial behavior

In this meta-analytic review, Hans J. Eysenck’s theory of criminality (Eysenck, 1964, Eysenck, 1977) serves as a theoretical framework for examining the relations between higher order personality dimensions and antisocial behavior (ASB). The three higher order dimensions examined are referred to as extraversion/sociability, neuroticism/emotionality, and impulsivity/disinhibition (see Sher & Trull, 1994), and they are likened to Eysenck’s dimensions of extraversion (E), neuroticism (N), and psychoticism (P), respectively (Eysenck & Eysenck, 1975) and Tellegen’s dimensions of positive emotionality (PEM), negative emotionality (NEM), and constraint (reversed) (CON), respectively (Tellegen, 1982). Ninety-seven samples, from 52 published and unpublished studies, were reviewed. The results indicated that among the “Big 3” personality dimensions, impulsivity/disinhibition is most strongly related to ASB and extraversion/sociability is least strongly related to ASB. Additional variables, including age and methodological differences, were found to moderate the associations between the personality dimensions and ASB.     

Relations Between Adolescent Ratings of Rothbart's Temperament Questionnaire and the HEXACO Personality Inventory

Conventionally, individual differences have been assessed using temperament measures for infants and children, and personality measures for adults. We chose to explore both temperament and personality to see whether a convergence exists specifically during adolescence. A sample of 225 adolescents completed Rothbart's Early Adolescent Temperament Questionnaire–Revised (EATQ–R), a 4-factor temperament scale, and the HEXACO Personality Inventory–Revised (HEXACO PI–R), a 6-factor personality scale. As hypothesized, we found significant relations between the 2 measures. However, there were some important differences between the 2 measures regarding Honesty–Humility, Openness, and Frustration that highlight the unique contributions of both instruments to understanding and measuring adolescent individual differences. As there is a relatively scant history of measuring temperament or personality in adolescence, it is sometimes difficult for researchers to decide which instrument is most appropriate. The results reported here suggest that either the EATQ–R or the HEXACO PI–R could be appropriate, depending on the specific research questions being asked.     

Impulsivity in adults: motor inhibition and time-interval estimation

There is a need for the development of behavioral measures of impusivity in order to elucidate the specific qualities of impulsive persons. The relationships between two behavioral measures of impulsivity and several personality inventories frequently used to assess inpulsivity were examined using 40 male Ss. The behavioral measures involved a motor-inhibition (MI) task and time-interval (TI) estimation. The personality measures included the Extraversion (E), Psychoticism (P) and Neuroticism (N) scales of the Eysenck Personality Questionnaire (EPQ), Barrat's Impulsivity Scale (BIS) and Gough's Socialization Scale (So). Significant relationships between MI scores and E, BIS and a proposed dimension of impulsivity obtained by the formation of E-P quadrants were found. In addition, performance on this task was related to So, P and E-N quadrants in the predicted directions. The consistency of these results supports the use of this task as a behavioral measure of impusivity in adults. Although personality inventory scores were not related to estimations, significant (negative) correlations were obtained between TI estimations and MI scores. The results indicate that TI estimation by itself is not an adequate measure of impulsivity, but does have implications for understanding impulsive behavior.     

EEG and personality differences between smokers and nonsmokers

Bilateral EEG spectra and personality were assessed in 46 habitual smokers and 46 nonsmokers, matched for age and gender. Smokers tended to have more activated EEG's than nonsmokers as indicated by higher dominant and median alpha frequencies and more fast and less slow frequency activity when relaxing with their eyes closed. Female smokers, compared to female nonsmokers, scored higher on personality trait measures of anger-proneness and psychoticism and lower on the Eysenck Personality (EPQ) conventionality/lie scale. Among males, the EPQ psychoticism scale, which has also been associated with anger, was the only personality measure found to significantly differentiate smokers from nonsmokers. The combination of EEG and personality findings is consistent with the view that there are differences between smokers and nonsmokers, such that smokers are more aroused and potentially irritated or angered more easily than nonsmokers.     

Sibling Relationships and Family Functioning in Siblings of Early Adolescents,Adolescents and Young Adults with Autism Spectrum Disorder

The purpose of the study was to investigate how family functioning (defined as the ability that family members hold to manage stressful events, and intimate and social relationships), the degree to which family members feel happy and fulfilled with each other (called family satisfaction), and the demographical characteristics of siblings (age and gender) impacted on sibling relationships. The Circumplex Model of Marital and Family Systems and Behavioral Systems constituted the theoretical frameworks that guided our study. Eighty-six typically developing adolescents and young adults having a sister or a brother with autism spectrum disorder were enrolled. Results indicated that the youngest age group (early adolescents) reported to engage more frequently in negative behaviors with their siblings with ASD than the two older age groups (middle adolescents and young adults). No significant differences were found among the three age groups regarding behaviors derived from attachment, caregiving and affiliative systems. Family satisfaction and age significantly predicted behaviors during sibling interactions. Suggestions on prevention and intervention programs were discussed in order to prevent parentification among typically developing siblings and decrease episodes of quarrels and overt conflicts between brothers and sisters with and without ASD.     

Nonshared environmental influences and personality differences in adult twins

The twin design was used to examine the importance of different experiences of siblings within the family and to identify relations between twins' personality differences and their differential experiences. A sample of 161 monozygotic and 74 dizygotic twin individuals between the ages of 18 and 75 years retrospectively reported on their different experiences when growing up. The Sibling Inventory of Differential Experience (SIDE) was used for the first time with a sample of twin siblings. In addition, the twins provided self-report measures of affect and personality. In contrast to results from a sibling adoption design, this study of twins showed greater evidence for genetic variance in the SIDE scales. Nevertheless, the SIDE showed significant associations with differences in personality and affect for monozygotic twins, which reflect pure environment-behavior relations.     

Siblings of Children with disabilities: Psychological and behavioural characteristics

The purpose of the current study was to assess the behavioural and psychological characteristics of siblings of children with disabilities and the perceptions of parents and children regarding sibling relationships. Participants included 32 children between 6 and 13 years of age, one-half with a younger sibling with a disability and one-half with a younger sibling without a disability. Analyses revealed a difference in children's perceptions of maternal partiality, with siblings of children with disabilities perceiving their mothers to be more partial to their siblings than did siblings of children without disabilities. Further, parents of children with disabilities indicated a greater difference in status/power between their child and his/her younger sibling than did parents of children without disabilities. No significant differences were found between groups on measures of behaviour problems, social competence, or self-esteem, supporting other research that has failed to find negative outcomes for siblings of children with disabilities. The implications of these results for parents and professionals are discussed.     

Personality characteristics of fetishists, transvestites and sadomasochists

Many theorists have suggested that sexual deviates adopt impersonal outlets because of difficulties in social interaction, particularly with adult members of the opposite sex. In order to investigate the personality and mental health of non-clinical fetishists, transvestites and sadomasochists, the Eysenck Personality Questionnaire was distributed to the members of clubs catering to these predilections. Completed questionnaires were obtained from 125 fetishists (mainly rubber and leather), 285 transvestites and transsexuals, and 133 sadomasochists. Comparison of personality scores with male controls revealed that these groups of men are relatively introverted, neurotic and slightly higher on psychoticism. However, their levels of neuroticism and psychoticism were not so high as to be comparable with clinical samples of neurotics, psychotics or even patients with sex problems. Analysis of individual items in the EPQ showed that the deviant groups were more shy, lonely, sensitive and depressed than controls and were less likely to enjoy telling jokes, all of which suggests some difficulty with social skills. Other questions concerning their social background and upbringing revealed that the deviant groups were more likely to be without a steady partner, to have perceived their upbringing as restrictive and to have disliked their mother. However, it was not possible to implicate the experience of corporal punishment in childhood with any of these sexual preferences.     

Personality and relaxation therapy: changes among clinical and normal subjects

There are increasing numbers of self-referral stress-management programs, a few of which use group-relaxation techniques, but few data are available on the personalities of the symptomatic and asymptomatic clients who attend or on any changes in personality after the program. Scores on the Eysenck Personality Inventory, Multiple Health Locus of Control, and State-Trait Anxiety Inventory as well as demographic information were obtained from 255 adults who attended a 10-session, university-based, group-relaxation program. The symptomatic clients reported significantly less anxiety, less neuroticism, were more extraverted and ascribed less of their behavior to chance at a 1 month post-treatment follow-up than at intake. The small group of asymptomatic clients also reported less anxiety and neuroticism at the follow-up. There were no sex differences on the Eysenck inventory or the anxiety scales but there were for the Multiple Health internal and control scales. It was concluded that group relaxation appeared to improve mental health scores effectively for both stressed and nonstressed adults and that age was significantly related to some personality scores.     

Students' Personality Traits and Learning Approaches

This study examined students' usage of deep and surface approaches to learning as well as the relationship between students' personality attributes and their approaches to learning. Participants were 284 undergraduate education students registered with a South African regular university (females = 195, males = 89). They completed the Revised two-factor Study Process Questionnaire (R-SPQ-2F) (Biggs, Kember, & Leung (2001) and Eysenck Personality Questionnaire (EPQ) (Eysenck & Eysenck, 1975, 1985). Data were analysed for differences in proportion endorsing learning approach type (deep, surface) and the association between learning approach and personality attributes. The students self-reported to use predominantly deep learning strategies and lower rather than high surface strategies. The personality attributes of Extraversion and Neuroticism were unrelated to self-reported primary learning strategy.     

Cognitive functioning of older people in relation to social and personality variables

Age differences in performance on memory measures and in subjective ratings of memory adequacy were examined in the context of 12 social, personality, adjustment, and lifestyle measures. Participants were 285 men and women, aged 65 to 93, of middle- and working-class backgrounds. A series of multivariate and univariate analyses revealed that a large proportion of the age differences and virtually all of the social-class differences on memory measures could be accounted for by contextual variables, with education, intellectual activity, extroversion, neuroticism, and lie scores (on the Eysenck Personality Inventory) all accounting for more of the variance in memory performance than did age. Self-rated memory adequacy was not correlated with performance, and although the expected finding of lower ratings by older participants was obtained with the working-class group, the opposite was true for the middle-class group. Implications of these results for understanding age differences in memory are discussed.     

Episode cognition and personality: A multidimensional analysis

The aim of the present study was to examine the relation between personality variables and the way an individual cognitively represents and interprets various interaction situations. A sample of typical and recurring interaction episodes within a student milieu was first elicited using a free response diary method. In the main study, subjects from the same subcultural milieu were asked to (a) complete a battery of personality assessment measures, including measures of social anxiety and social competence, and (b) indicate their perception of the interaction episodes of the group. Their judgements of the episodes were analyzed using Carroll and Chang's (1970) Individual Differences Multidimensional Scaling (INDSCAL) procedure, indicating that four characteristics, subjective self-confidence, evaluation, seriousness, and involvement defined subjects' implicit view of the episode space. A canonical correlation analysis between the personality measures and each subject's episode cognition weights indicated a significant relation between these two groups of variables. The link between social skills and episode cognition style was further explored by a multiple discriminant analysis of the episode cognition weights of subjects who scored in the top and the bottom third of the sample on a composite social skills measure. The results are interpreted as providing significant support for recent cognitive theories of personality, and the link between episode cognition and personality variables is considered. The role of episode cognition in social skills assessment and therapy is also discussed, with a view toward exploring the relevance of the findings for applied areas.     

Exploring issues of personality measurement and structure through the development of a short form of the Eysenck Personality Profiler

In this article, we develop a revised short form of the original Eysenck Personality Profiler (EPP; H. J. Eysenck & Wilson, 1991). In addition, we address topics of broad theoretical importance such as the recurrent empirical finding of correlations between conceptually orthogonal personality dimensions and the possibility that gender differences in these dimensions are partly spurious. In Study 1 (N = 227), we demonstrate that the existing short form of the EPP (EPP-SF; H. J. Eysenck, Wilson, & Jackson, 1996) provides a poor fit to the data and we develop a revised well-fitting version. In Study 2, we retest this version on an independent new sample (N = 3,374) where it is again found to fit the data well. We show that most of the structural and measurement parameters of the revised EPP-SF are invariant across genders. Structured means analysis indicated a significant gender difference in Psychoticism, with men scoring higher than women, but no differences in Extraversion or Neuroticism. Our discussion focuses on issues concerning personality measurement and structure, including an examination of the role of confirmatory factor analysis in personality research.