Sociability/impulsivity and caffeine-induced arousal: Critical flicker/fusion frequency and procedural learning

The influence of sociability/impulsivity in caffeine-induced arousal effects was investigated in two separate experiments: Experiment 1 examined critical flicker/fusion frequency change scores (ΔCFFT) in 60 subjects; and Experiment 2 investigated procedural learning in 30 subjects. In the two experiments, subjects received either caffeine citrate (500 mg) or placebo. The pattern of results was consistent across both studies:(1) a strong interactive effect of sociability (as measured by the EPQ extraversion scale) by caffeine/placebo which showed that (a) subjects low in sociability showed the greatest increase in ACFFT and learned most under placebo, while the reverse was true under caffeine; (b) subjects high in sociability, showed no increase in ΔCFFT and learned least under placebo, while the reverse was true under caffeine; and (2) in neither experiment did impulsivity (as measured by the EPS impulsiveness scale) significantly interact with caffeine/placebo. The results are consistent with Eysenck's (The Biological Basis of Personality, 1967) theory of personality in suggesting that subjects low in sociability are highly arousable under low-arousal (placebo) but over-aroused under high-arousal (caffeine), with the reverse pattern of effects holding for subjects high in sociability. The implications of these data for the respective roles of sociability and impulsivity components of extraversion in arousal-mediated performance are discussed.     

Personality and multidimensional arousal: A study of two dimensions of extraversion

Recent research has provided conflicting accounts of the effects of extraversion on arousal, and of the role of arousal in effects of extraversion and impulsivity of performance. Data are presented from a study of the inter-relationships of various dimensions of extraversion, self-report arousal and physiological arousal. Subjects also performed a verbal intelligence test. A composite measure of skin conductance and heart rate was significantly positively correlated with a self-report general arousal measure. 16PF Extraversion, and two primary extraversion factors, F and H, were significantly negatively correlated with physiological arousal, and/or one dimension of self-report arousal. The relationship between extraversion and arousal was not affected by time of day. An interactive effect of time of day, F and general arousal on performance was found, but there were no significant effects of H on performance. Relationships between extraversion and arousal may be epiphenomenal to interactive effects of extraversion or impulsivity and arousal on performance.     

Extraversion: sociability and impulsivity?

The sociability and impulsivity components of extraversion were studied. Thirty experimental items were written to assess different aspects of sociability and impuslivity. These items, along with the 24 extraversion items of the MPI, were administered to 146 college students. Factor analyses of experimental items indicated that neither sociability nor impulsivity is unitary. Correlations among these sociability and impulsivity factors and the MPI extraversion items indicated that MPI extraversion is essentially a measure of one aspect of sociability: the quantity of social relationships. Extraversion touches on but does not adequately sample either the intensity (quality) of social relationships or aspects of impulsivity.     

Sociability/impulsivity and attenuated dopaminergic arousal: critical flicker/fusion frequency and procedural learning

Two experiments examined the interaction of sociability (Soc) and impulsivity (Imp) components of extraversion and reduced dopamine activity (by haloperidol) on critical flicker/fusion frequency change scores (ACFFT) and procedural learning. In double-blind designs, subjects received either haloperidol (5 mg) or placebo; Soc and Imp were randomly sampled. In Experiment 1, Drug × Imp, and Drug × Imp × Soc interactions were found on ΔCFFT; in Experiment 2, a drug × Soc interaction was found on procedural learning. In both experiments, introverts seemed over-aroused under placebo (putatively due to the medical context), more optimally aroused under haloperidol; for procedural learning, extraverts seemed more optimally aroused under placebo, less optimally aroused under haloperidol. These data indicate that both Soc and Imp mediate the effects of arousal; Drug × Imp effects my conceal joint effects of Soc × Imp; and that Soc shows more consistent effects than Imp. These data complement a previous study of Soc/Imp and caffeine-induced arousal (Corr, Pickering & Gray, 1995), and lend support to H. J. Eysenck's (1967) arousal model of Extraversion.     

Differential relationships of extraversion,impulsivity, and sociability to study habits

Reanalysis of data on library study habits presented by J. B. Campbell and C. W. Hawley (Journal of Research in Personality, 1982, 16, 139–148) revealed differential utility for the EPI extraversion scale and its components, impulsivity and sociability. Individuals studying in locations that provided greater external stimulation had significantly higher extraversion and impulsivity, but not sociability, scores than individuals studying elsewhere in the library. Impulsivity was more strongly associated than sociability with preferred noise levels, frequency of study breaks, and importance and preferred levels of socializing opportunities, but less strongly associated with preferred levels of crowdedness. Findings are discussed in terms of the interpretation, reliabilities, and theoretical context of the subscales.     

Multidimensional arousal states,diurnal rhythms,cognitive and social processes,and extraversion

Based on Thayer's two-dimensional arousal model, several questions were investigated, including the relationship between endogenous diurnal rhythms of energetic arousal and various psychological functions. Also investigated were theoretical issues relating to Eysenck's arousal theory of extraversion and neuroticism, and associations involving the Morningness-Eveningness Questionnaire (MEQ). Self-reported arousal measurements were taken from 18 participants every hour of the waking day for 6 separate days. Substantial relationships were observed between obtained diurnal cycles of energetic arousal and previous interview estimates by the same individuals of best and worst times for social, mood, and intellectual functions. Eysenck's Neuroticism scores were found to predict overall tension ratings, and tense arousal showed an interaction between Extraversion and time of day similar to Blake's body temperature findings. Moderate support was also found for the validity of the MEQ. Discussed were various possible modifications of Eysenck's arousal theory based on Thayer's two-dimensional model.     

The effect of consumers' diurnal preferences on temporal behavior

The purpose of this study is to determine whether customers' diurnal preferences, tested at different times of the day, affect their responses and behavior. Three studies explore whether synchrony between the peak circadian arousal period and the time of participant testing influenced participants' temporal perception and behavior. Overall, the results imply a robust synchrony and time-of-day effects on the dependent variables. The authors discuss the theoretical significance of their findings and the managerial implications for consumer research and practice.     

Dishabituation and spontaneous recovery of the electrodermal orienting response: Effects of extraversion,impulsivity, sociability,and caffeine

The relationship between extraversion and psychophysiological indices of arousal is not yet fully understood. The present study attempted to further clarify this relationship by using caffeine to systematically manipulate arousal. Subjects pretested on the Eysenck Personality Inventory were given caffeine or a placebo, then underwent habituation, dishabituation, and spontaneous recovery of the electrodermal OR. Separate analyses examined the main and interactive effects of extraversion, impulsivity, and sociability with caffeine. Several tonic and phasic measures showed group reversal effects, with introverts having higher tonic levels and larger phasic responses under placebo conditions and extraverts having larger phasic responses and higher tonic levels under caffeine. Although both tonic and phasic responses were differentially affected, the group reversal effects occurred at different points in time on tonic than they did on phasic measures relative to the theoretical buildup of inhibition. The findings for impulsivity were quite consistent with those for extraversion, and both sets of results were generally supportive of the Eysenck hypothesis.     

The relationship between the EPI extraversion score and impulsiveness on a perceptual-motor task

This paper describes an investigation of the relationship between extraversion and impulsiveness. These two traits were measured respectively by the Eysenck Personality Inventory (EPI) and the IES Arrow-Dot test. The subjects were 50 males and 50 females matched for age. Arrow-Dot impulsiveness was found to correlate significantly with extraversion in both samples. In the female sample Arrow-Dot impulsiveness correlated only significantly with the ‘impulsiveness’ component of extraversion. In the male sample both the ‘impulsiveness’ and ‘sociability’ components of the extraversion factor contributed about equally to its variance.     

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.     

A Psychometric Investigation of the Usefulness of the Easi-III Temperament Survey in the Australian General Population

The psychometric properties of Buss and Plomin's EASI-III Temperament Survey were examined for a random sample of 290 respondents from the Australian general population. These data support the use of the emotionality, activity and sociability scales with some minor modifications, but cast doubt on the impulsivity scale. Not only did impulsivity emerge as a multidimensional construct, but its components related to other temperaments in markedly different ways. The preliminary analyses also suggested that the EASI-III could be used to measure other constructs, the most important of which are neuroticism and extraversion. The advantages offered by the EASI-III over currently available instruments are discussed: in particular, the simplicity and clarity of the items and the well-articulated sampling framework for their selection.     

The interactive effect of personality, time of day, and caffeine: a test of the arousal model

The personality dimension of introversion/extraversion is one of the few personality dimensions that can be reliably identified from study to study and investigator to investigator. The importance of this demension within personality theory is due both to the stability of the trait and the influential theory of H. J. Eysenck. The basic assumption in Eysenck's theory of introversion/extraversion is that the personality differences between introverts and extraverts reflect some basic difference in the resting level of cortical arousal or activation. Assuming that there is a curvilinear relationship (an inverted U) between levels of stress and performance leads to a test of this arousal theory. That is, moderate increases in stress should hinder the performance of introverts who are presumably already highly aroused. However, the same moderate increase in stress might help the performance of the presumably underaroused extraverts. Revelle, Amaral, and Turriff reported that the administration of moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task similar to the verbal test of the Graduate Record Examination. Assuming that caffeine increases arousal, this interaction between introversion/extraversion and drug condition supports Eysenck's theory. This interaction was explored in a series of experiments designed to replicate, extend, and test the generality of the original finding. The interaction between personality and drug condition was replicated and extended to additional cognitive performance tasks. However, these interactions were affected by time of day and stage of practice, and the subscales of introversion/extraversion, impulsivity, and sociability, were differentially affected. In the morning of the first day, low impulsives were hindered and high impulsives helped by caffeine. This pattern reversed in the evening of the first day, and it reversed again in the evening of Day 2. We concluded that the results from the first day of testing require a revision of Eysenck's theory. Instead of a stable difference in arousal between low and high impulsives, it appeared that these groups differed in the phase of their diurnal arousal rhythms. The result is that low impulsives are more aroused in the morning and less aroused in the evening than are the high impulsives. A variety of peripheral or strategic explanations (differences in caffeine consumption, guessing strategies, distraction, etc.) for the observed performance increments and decrements were proposed and tentatively rejected. It seems probable that some fundamental change in the efficiency with which information is processes is responsible for these performance changes.     

Time-of-day affects prospective memory differently in younger and older adults

The goal of this study was to investigate the impact of circadian arousal on prospective memory performance as a function of age. We tested a younger (18–34 years) and an older group (56–95 years) of participants on- and off-peak with regard to their circadian arousal patterns in a computer-based laboratory experiment. For the prospective memory task, participants had to press a particular key whenever specific target words appeared in an ongoing concreteness-judgment task. The results showed that prospective memory performance was better on- than off-peak in younger but not older participants. Younger participants consistently outperformed older participants in all conditions. We conclude that prospective remembering underlies time-of-day effects which most likely reflect controlled processes.     

Personality,time of day and visual perception: Preferences and selective attention

The study examined the relationships between Eysenck's personality dimensions and certain aspects of visual perception employing a sample of 83 females. Interaction effects of time of day were emphasized. As to personality, the focus was on the extraversion components Impulsivity (I) and Sociability (S). As to perception, two major aspects were focused on: (1) preferences for (a) colour and (b) form, and (2) selective attention to the salient feature (form complexity) of present stimuli using a person-centered ANOVA approach. The personality by time-of-day interaction hypothesis was only supported for the I (and not S) component, under conditions 1a and 2; in the morning high I scorers preferred more stimulating colours, and paid less attention to form complexity, than low I scorers whereas a reverse pattern emerged in the evening. Neuroticism showed no relationship to perception whereas psychoticism was found to be positively related to colour reactivity and negatively related to reactivity to meaningfulness of stimuli. The findings are discussed in the context of theories about cortical arousal, diurnal rhythm differences, and ‘narrowed attention’.     

Comparison of EPI and psychoticism scales with measures of the five-factor model of personality

The need for a comprehensive model of personality traits acceptable to the entire community of personality researches has often been acknowledged. In this article, two such models are compared. Eysenck scales measuring neuroticism, extraversion, psychoticism and lie are correlated with self-report and peer-rating measures of the five-factor model—neuroticism, extraversion, openness to experience, agreeableness and conscientiousness—in a sample of adult men and women. Findings suggest that: (1) neuroticism and extraversion factors from the two systems match well; (2) sociability and impulsivity are distinguishable traits, but both fall within the broad domain of extraversion; (3) the EPI L scale measures aspects of several substantive traits rather than a response bias; (4) openness to experience is not well-represented in the Eysenck system; and (5) psychoticism corresponds most closely to the low poles of agreeableness and conscientiousness.     

Extraversion and rapid tapping: reactive inhibition or general cortical activation as determinants of performance differences

Two samples of subjects (n_tot = 22) scoring high or low on EPI-E tapped a morse-key as fast as possible over a 2-min period. As predicted, extraverts showed a lower tapping performance than introverts with differences between groups increasing significantly over time due to greater delays among the extraverts. Within the E dimension tapping differences could be shown to depend significantly only on the subfactor impulsiveness but not on sociability. There were no differences between groups, however, in frequency of involuntary rest pauses. Therefore the effects of extraversion on tapping performance should be explained more in terms of underlying differences in cortical arousal level than in terms of intermittent blocks as part of inhibitory potentials.     

The nature of extraversion: a genetical analysis.

A biometrical-genetical analysis of twin data to elucidate the determinants of variation in extraversion and its components, sociability and impulsiveness, revealed that both genetical and environmental factors contributed to variation in extraversion, to the variation and covariation of its component scales, and to the interaction between subjects and scales. A large environmental correlation between the scales suggested that environmental factors may predominate in determining the unitary nature of extraversion. The interaction between subjects and scales depended more on genetical factors, which suggests that the dual nature of extraversion has a strong genetical basis. A model assuming random mating, additive gene action, and specific environmental effects adequately describes the observed variation and covariation of sociability and impulsiveness. Possible evolutionary implications are discussed.     

The relationship of age and extraversion to arousal and performance on a sustained attention task: A cross-sectional investigation using the Mackworth clock-test

H. J. Eysenck has postulated—and received some empirical support for—an inverse relationship between extraversion and arousal level. Age and extraversion have been found to be negatively correlated. These two outcomes led to the conclusion that arousal level must be increasing with age. This conclusion, however, runs counter to evidence which indicates a lowered arousal with old age. In an attempt to resolve this apparent conundrum a sample of 134 men from 32 to 91 years of age participated in the Mackworth Clock-Test of vigilance during which their arousal level was measured by electrodermal activity. One measure of arousal was unrelated to extraversion both within and across young, middle, and old age groups. For the second measure of arousal as age increased a decrease in arousal level was observed and the relationship of extraversion and arousal was found to be a function of age: inverse for young, none for middle-aged, direct for old. In addition no relation was found between vigilance performance and extraversion.     

The influence of background music on learners with varying extraversion: Seductive detail or beneficial effect?

Seductive details in general affect learning and cognitive load negatively. However, especially background music as a seductive detail may also influence the learner's arousal, whose optimal level depends on the learner's extraversion. Therefore, the effects of extraversion and background music on learning outcomes, cognitive load, and arousal were investigated. We tested 167 high school students and found better transfer outcomes for the group with background music. They also reported higher germane load, but no impact of background music on extraneous cognitive load or arousal was found. In the group without background music, learners with higher extraversion reached better recall scores, which was not found in the group with background music. Results may cautiously be interpreted that there is a beneficial impact of background music that compensates for the disadvantages of low extraverted learners and which cannot be explained through arousal.     

Electrodermal responses to movie stressors: Nicotine × extraversion interactions

Support was found for Eysenck's hypothesis that the effects of smoking sized doses of nicotine on cortical and electrodermal activity are functions of extraversion and the degree of externally-induced arousal. Responses to scenes that elicited moderate electrodermal and emotional responses followed the predicted extraversion ☆ nicotine interaction for electrodermal measures, but not for self-reported emotions, heart rate or electromyographic measures. The failure of the Ss to demonstrate an extraversion ☆ nicotine interaction when high-intensity stimuli were used (Gilbert and Hagen, 1980) is also interpreted as consistent with Eysenck's hypothesis.