The personality theories of H.J. Eysenck and J.A. Gray: a comparative review

On the heritability of job satisfaction: the mediating role of personality

In this article the authors investigate the extent to which traits reflecting individual differences in personality and affectivity explain or mediate genetic influences on job satisfaction. Using estimates of the dispositional source of job satisfaction according to 2 dispositional frameworks--the five-factor model and positive affectivity-negative affectivity (PA-NA)--and behavioral-genetic estimates of the heritabilities of job satisfaction and the dispositional factors, the authors computed the proportion of genetic variance in job satisfaction that is explained by these trait frameworks. Results indicate that the affectivity model is a stronger mediator of genetic effects on job satisfaction than the five-factor model. PA and NA mediate about 45% of the genetic influences on job satisfaction, whereas the five-factor model mediates approximately 24% of these genetic effects.

Healthy high-hostiles evidence low-alpha power (7.5-9.5Hz) changes during negative affective learning

The present experiment was designed to better understand the impact of positive and negative emotional processing among low- and high-hostile individuals. Based on previous research which found increased sympathovagal balance among low-hostiles to the negative version of the Affective Auditory Verbal Learning Test (AAVL), it was hypothesized that low-hostiles would experience increased cortical arousal to this stimulus whereas their high-hostile counterparts would not. As expected, low-hostiles experienced significantly reduced low-alpha power (7.5-9.5Hz) relative to high-hostiles during the presentation of the negative AAVL. In a replication of prior research, significant primacy and recency effects were noted for the negative and positive word lists, respectively. Results are discussed in terms of cerebral activation theory and the potential impact of emotional processing among high-hostile individuals and their likelihood to develop coronary heart disease.

Trait as Default: Extraversion, Subjective Well-Being, and the Distinction Between Neutral and Positive Events

On the basis of prior work suggesting that trait self-knowledge serves a "fill-in" function when event-specific information is missing (M.D. Robinson & G. L. Clore, 2002a), we sought to demonstrate that extraversion is a more reliable predictor of subjective well-being (SWB) judgments among certain individuals than among others. Four studies involving a total of 260 participants revealed that the extraversion-SWB relation was relatively weaker among those quick to appreciate the distinction between neutral and positive events in a choice reaction-time task; by contrast, it was stronger among those slow to recognize this distinction. The findings suggest that extraversion scales measure (among other things) beliefs about SWB that differentially contribute to judgments among those less capable of making evaluative distinctions at encoding.

Introversion and individual differences in middle ear acoustic reflex function

A growing body of psychophysiological evidence points to the possibility that individual differences in early auditory processing may contribute to social withdrawal and introverted tendencies. The present study assessed the response characteristics of the acoustic reflex arc of introverted-withdrawn and extraverted-sociable individuals. Introverts displayed a greater incidence of abnormal middle ear acoustic reflexes and lower acoustic reflex amplitudes than extraverts. These findings were strongest for stimuli presented at a frequency of 2000 Hz. Results are discussed in light of the controversy concerning the anatomic loci (peripheral vs. central neuronal activity) of the individual differences between introverts and extraverts in early auditory processing.

The epistemic benefits of trait-consistent mood states: an analysis of extraversion and mood

One must consider both trait and state affect to predict individual differences in emotional processing. The present results document a novel trait-state interaction that is consistent with proposals concerning the epistemic functions of affect (A. R. Damasio, 1994). Four studies tested the effects of extraversion and mood on motivation-relevant processing. Study 1 measured naturally occurring mood, whereas Studies 2-4 manipulated mood. Extraverts were faster to link events to their personal motivations when in a positive mood state, whereas introverts were faster to do so in a neutral or negative mood state. Further findings indicate that this interaction affects attitude accessibility rather than event elaboration. Overall, the authors suggest that there are pragmatic benefits to trait-consistent moods, particularly for processing motivation-relevant stimuli.

Why introverts can't always tell who likes them: multitasking and nonverbal decoding

Despite personality theories suggesting that extraversion correlates with social skill, most studies have not found a positive correlation between extraversion and nonverbal decoding. The authors propose that introverts are less able to multitask and thus are poorer at nonverbal decoding, but only when it is a secondary task. Prior research has uniformly extracted the nonverbal decoding from its multitasking context and, consequently, never tested this hypothesis. In Studies 1-3, introverts exhibited a nonverbal decoding deficit, relative to extraverts, but only when decoding was a secondary rather than a primary task within a multitasking context. In Study 4, extraversion was found to correlate with central executive efficiency (r = .42) but not with storage capacity (r = .04). These results are discussed in terms of arousal theories of extraversion and the role of catecholamines (dopamine and norepinephrine) in prefrontal function.

An fMRI study of personality influences on brain reactivity to emotional stimuli

Functional imaging studies have examined which brain regions respond to emotional stimuli, but they have not determined how stable personality traits moderate such brain activation. Two personality traits, extraversion and neuroticism, are strongly associated with emotional experience and may thus moderate brain reactivity to emotional stimuli. The present study used functional magnetic resonance imaging to directly test whether individual differences in brain reactivity to emotional stimuli are correlated with extraversion and neuroticism in healthy women. Extraversion was correlated with brain reactivity to positive stimuli in localized brain regions, and neuroticism was correlated with brain reactivity to negative stimuli in localized brain regions. This study provides direct evidence that personality is associated with brain reactivity to emotional stimuli and identifies both common and distinct brain regions where such modulation takes place.