Biological Bases of Maternal Attachment

In recent years, there has been growing interest in investigating the processes affecting caregiving behavior. Recent studies of human and nonhuman primates have suggested that hormones can account, at least in part, for changes in caregiving motivation during pregnancy and the postpartum period and for variability in caregiving motivation and behavior among individuals. Although hormones may not be the primary determinants of caregiving, future research cannot afford to overlook the contribution that biological processes can make to normative and pathological attachment and parenting.     

创造性的生理研究新进展

创造性的生理基础很复杂。关于创造性生理基础的研究集中在大脑皮质激活与脑半球不对称两个方面。研究发现,大脑皮质激活状态对创造性有影响,低水平的皮质激活,特别是低水平的前额叶激活,较有利于创造性．研究还发现,创造性和左右半球不对称活动有关,处于创造状态时,右半球相对要比左半球激活程度更高。     

Extraversion and happiness

The relationship between extraversion and happiness or subjective well-being (SWB) is one of the most consistently replicated and robust findings in the SWB literature. The present study was conducted in order to examine three key aspects of the relationship: (1) Whether it is primarily substantive in nature, or a product of self-report response artifacts, such as social desirability; (2) What the underlying systems or mechanisms involved in the relationship are; and (3) Whether Eysenck's two dimensions of extraversion and neuroticism combine additively or interactively in their influence upon an individual's level of SWB. The results are supportive of the substantive nature of the relationship, and suggest that both situational and personality factors combine to produce the positive correlation between extraversion and SWB. In terms of the interaction of extraversion and neuroticism, the results are mixed in supporting both an additive and interactive relationship.     

Extraversion,neuroticism, psychoticism and self-reported delinquency: Evidence from eight separate samples

Eight separate samples of high school and university students (Total N = 410) in Britain and Canada were used to test predictions from Eysenck's theory that delinquents should be high scorers on scales of extraversion, neuroticism, and psychoticism. Self-report paper- and pencil-questionnaire measures of both personality and delinquency were administered under conditions that ensured anonymity. The evidence showed clear support for a relationship between high delinquency scores and high scores on both extraversion and psychoticism. These relationships held up across diverse samples and different ways of analyzing the data. No support was found for a relationship between delinquency scores and the dimension of neuroticism.     

Extraversion and exercise addiction

Extraversion has been suggested as a factor associated with addiction. This claim was tested in relation to exercise addiction. Twelve exercise addicts were compared with 12 nonaddicted individuals who were committed to regular exercise and with 12 nonexercising individuals drawn from the same student population. Addicted exercisers did not differ from nonaddicted exercisers in extraversion, although exercisers as a group were more extraverted than nonexercisers. The results are interpreted as evidence against the claim that extraversion is a component of the addictive personality profile.     

Extraversion and emotional reactivity

Six mood induction studies and a meta-analysis were conducted to test 2 models of the extraversion-pleasant affect relation. The affect-level model suggests that extraverts should be happier than introverts in both neutral and positive mood conditions. The reactivity model posits that extraverts react particularly strongly to pleasant stimuli and that they should be happier than introverts only in positive conditions. In all studies, extraverts failed to exhibit greater emotional reactivity when pleasantness items were analyzed. When activated positive affect items were analyzed, results were mixed. The meta-analysis confirmed that there is only a slight reactivity effect overall, and this effect emerges only in activated positive affect items. Furthermore, the meta-analysis showed that the correlation in neutral conditions is strong enough to support the affect-level model.     

The Interaction of Extraversion and Anxiety Sensitivity on Social Anxiety: Evidence of Specificity Relative to Depression

Neuroticism and extraversion have been linked to the etiologies and course of anxiety and mood disorders, such that neuroticism is broadly associated with numerous disorders and extraversion is most strongly associated with social anxiety and depression. While previous research has established the broad associations between temperament and emotional disorders, less is known about the specific, proximal factors that are associated with them, and very few studies have situated these risk factors into a larger etiological model that specifies how they may relate to one another. The current study examined the interaction of extraversion and anxiety sensitivity (AS) in predicting social anxiety symptoms in a large, diagnostically diverse clinical sample (N = 826). Symptoms were assessed with self-report and dimensional interview measures, and regression analyses were performed examining the main effects and interaction of extraversion and AS (examining both total and lower-order components) on social anxiety. Results showed that at higher levels of AS, the inverse relationship between extraversion and social anxiety was stronger, and the social concerns component of AS is responsible for this effect. This interaction was also observed with regard to depression symptoms, but the interaction was not present after accounting for shared variance (i.e., comorbidity) between depression and social anxiety symptoms. Clinical and theoretical implications of the results are discussed.     

Voice Expression and Rated Extraversion

Eighteen Ss listened to neutral and emotional passages recorded by 22 speakers who had taken the Eysenck Personality Inventory. The estimates of extraversion arrived at by the 18 listener-judges did not correlate significantly with the EPI measure of extraversion. Despite this lack of criterion validity, some voices were clearly and reliably rated as more introverted or extraverted than others. The judges' own degree of extraversion was not a significant factor in the judgments.     

Extraversion and the detection of deception

Extraversion, neuroticism and threat of punishment were investigated in a detection of deception paradigm. Half of the 96 subjects, by instruction, had committed a mock crime while the other half were innocent of such an act. Extraversion was related to accuracy of detection such that those with high scores on this dimension were more likely to be classified correctly as guilty or innocent. This result had been predicted on the basis that detection is not determined by overall physiological responsiveness to questions but by contrasting responsiveness to critical and non-critical questions. Thus those high on extraversion, who were conceived of as difficult to arouse, responded only to the critical questions in the test while the more arousable introverts masked contrast by responding indiscriminately to both critical and non-critical questions. Neither of the other variables, neuroticism and threat of punishment, were related to detection.     

Trait Extraversion and Dopamine Function

An influential theory within personality neuroscience suggests that trait extraversion is underpinned by individual differences in dopamine function. In a review of the relevant literature, we evaluate this theory in light of the evidence from molecular genetics, neuroimaging, and psychopharmacology. Evidence linking individual differences in extraversion with dopamine‐relevant genes, structural volume of dopamine‐rich brain regions (e.g., in striatal and ventral prefrontal areas), dopamine receptor availability, and frontal alpha asymmetry is mixed at best. Evidence concerning both scalp recorded (electroencephalogram) and hemodynamic (functional magnetic resonance imaging) neural responses to rewards appears somewhat more promising. Perhaps the best evidence concerns extraversion‐dependent responses – both neural and behavioural – to dopaminergic drugs. Future research in this area must go beyond the demonstration of theoretically consistent associations and attempt to provide more specific causal evidence for the dopamine hypothesis of extraversion. A further challenge is to expand this hypothesis to incorporate other neurobiological processes that are likely to underlie this trait.     

Extraversion and neuroticism in rats

A series of animal experiments is described, the aim of which was to test the hypothesis that the personality dimensions of extraversion-introversion and neuroticism-stability could be demonstrated and measured in rats. The open-field situation was used, as well as other tests, varying the amount of stress induced in the rats, and positive results, in line with prediction, are reported. It does seem possible to find animal analogues of human personality types, even in lowly mammals, such as rats.     

Bases for Object Individuation in Infancy: Evidence From Manual Search

Two studies exploited a new manual search methodology to assess the bases on which 10- to 12-month-olds individuate objects. Infants saw 1 or 2 objects placed inside an opaque box, into which they could reach. Across conditions, the information specifying 2 objects differed. The dependent measures reflected persistence of reaching into a box that was empty regardless of whether an object should have remained. Success consists of little reaching after all objects are removed and persistent reaching for an object not yet retrieved. Given spatiotemporal information for 2 objects, both age groups succeeded. Given only property or kind information, only 12-month-olds succeeded. Despite disparate information-processing demands, this pattern converges with looking time data (Xu & Carey, 1996; Xu, Carey, & Welch, 1999), suggesting a developmental change orthogonal to that of executive function. This change may reflect the emergence of kind representations.     

Extraversion and attitude towards capital punishment

Male and female Canadian undergraduate students identified as extraverts or introverts on the basis of the Eysenck Personality Inventory were administered a questionnaire measuring attitude towards Capital Punishment. Both effects of sex and personality were significant, males and extraverts reporting stronger beliefs in Capital Punishment than females and introverts. These results were interpreted as providing support for Eysenck's proposal that the social attitude dimension of Toughmindedness reflects the personality trait of Extraversion.     

Psychophysiological components of imagery

McGuigan’s neuromuscular model of information processing (1978a, 1978b, and 1989) was investigated by electrically recording eye movements (electro-oculograms), covert lip and preferred arm responses (electromyograms), and electroencephalograms. This model predicts that codes are generated as the lips are uniquely activated when processing words beginning with bilabial sounds like “p” or “b,” as is the right arm to words like “pencil” that refer to its use. Twelve adult female participants selected for their high imagery ratings were asked to form images to three orally presented linguistic stimuli: the letter “p,” the words “pencil” and “pasture,” and to a control stimulus, the words “go blank.” The following findings were significant beyond the 0.05 level: an increased covert lip response only to the letter “p,” increased vertical eye activity to “p” and to the word “pencil,” right arm response only to the word “pencil,” and a decreased percentage of alpha waves from the right 02 lead only to the word “pasture.” Since these covert responses uniquely occurred during specific imagery processes, it is inferred that they are components of neuromuscular circuits that function in accord with the model of information processing tested.     

Extraversion,Neuroticism, and Face-Name Learning

Previous research has attempted to relate personality traits to paired-associate learning. We tested name recall as a function of extraversion and neuroticism (as assessed by the Eysenck Personality Inventory) and task difficulty. Face photographs were paired with one of three levels of information: names only (an easy task); names and occupations; or names, occupations, and interests (a difficult task). On the easy and difficult tasks, extraverted subjects recalled more names than did subjects scoring at the median or below on that trait. Contrary to expectations, subjects scoring high on neuroticism recalled more names than did subjects scoring low on that trait. Neither trait was significantly related to recall on the moderately difficult task. There was no interaction between traits for name recall, but there was for interests: Neurotic introverts were significantly impaired at recalling interests, whereas the other subjects recalled interests better than names. These findings thus differ from those of paired-associate learning tasks using words and nonsense syllables.