Deep Down
Kevin Beaver et al.
Developmental Psychology, forthcoming
Abstract:
Although educational attainment has been found to be moderately heritable, research has yet to explore candidate genes for it. Drawing on data from the National Longitudinal Study of Adolescent Health, in the current study, we examined the association between polymorphisms in three dopaminergic genes (DAT1, DRD2, and DRD4), a dopamine index, and educational attainment. Statistically significant effects were found for DAT1, DRD2, DRD4, and the dopamine index for highest level of education. This study is the first to our knowledge that links measured genes to educational attainment.
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Bitter struggle for survival: Evolved bitterness embodiment of survival motivation
Bin-Bin Chen & Lei Chang
Journal of Experimental Social Psychology, forthcoming
Abstract:
In four experiments, we tested the hypothesis that survival motivation is grounded in the physical experience of bitter taste. Chinese (Experiment 1) and non-Chinese participants (Experiment 2) who tasted a bitter drink were quicker than the control participants who drank plain water in responding to survival-related words in a lexical decision task. Chinese participants who chewed bitter lotus root were more likely to discount the future than those who chewed sour lemon (Experiment 3). Finally, surprise retention tests revealed that experiencing a bitter rather than sweet taste led to higher retention of words processed for survival rather than mating scenarios (Experiment 4). These findings support our prediction that the taste of bitterness embodies survival motivation because both are adaptations to harsh environment.
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Social class differences in n400 indicate differences in spontaneous trait inference
Michael Varnum et al.
Journal of Experimental Psychology: General, forthcoming
Abstract:
An emerging literature indicates that dispositional bias in causal attribution of social behavior is weaker for people with working-class (vs. middle-class) backgrounds. However, it is unknown whether this difference is also present in spontaneous forms of trait inference. In the current work, American undergraduates were asked to merely memorize many pairings of a target face and a trait-implying behavior. In a subsequent lexical judgment task, after each face was presented as a fixation, either an implied trait or its antonym was given as a target. As expected, participants with college-educated parents (middle class) showed a strong N400 event-related potential component to the antonym (vs. the implied trait), suggesting spontaneous trait inference during the memorization phase. In contrast, those with high-school-educated parents (working class) showed no such effect. It is important to note that the N400 spontaneous trait inference effect was associated with perceived significance of dispositions in accounting for social behaviors.
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Digit ratio and celebrity worship
HaengRyang Huh
Personality and Individual Differences, forthcoming
Abstract:
The current study tested the hypothesis that digit ratios would be associated with celebrity worship, especially among adolescents. Our sample consisted of 45 male and 61 female participants aged 12-14 years (M = 13.20, SD = 0.71). We measured the digit ratios on the participants' right hands and used the 23 items of the revised Celebrity Attitude Scale (CAS) to explore the degree to which participants engaged in celebrity worship. The average digit ratio was 0.95 (SD = 0.04) among male participants and 0.97 (SD = 0.05) among female participants. The mean CAS scores were 50.06 (SD = 20.63) for male participants and 64.49 (SD = 18.04) for female participants. The digit ratios for the entire sample were positively correlated with CAS scores (r = 0.29, p < 0.005). However, the digit ratios were positively correlated with CAS scores among female (r = 0.51, p < 0.001) but not male (r = -0.13, p = .394) participants. Our research found evidence of a significant positive correlation between 2D:4D ratios and celebrity worship in females but not in males, which indicated that females with lower digit ratios were less likely to worship celebrities.
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Erin Myers & Virgil Zeigler-Hill
Journal of Research in Personality, forthcoming
Abstract:
Narcissism is considered to be a pathological form of self-love but the extent to which narcissists actually like themselves is unclear. The present study utilized the bogus pipeline technique in order to examine how narcissists actually feel about themselves. Participants were 71 women who completed measures of narcissism and self-esteem before responding to a self-esteem measure under either bogus pipeline or control conditions. Women with high levels of narcissism reported lower levels of self-esteem in the bogus pipeline condition than the control condition. This suggests that women with high levels of narcissism may not actually feel as good about themselves as they often claim.
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Paige Harden, Patrick Quinn & Elliot Tucker-Drob
Developmental Science, forthcoming
Abstract:
Sensation seeking is associated with an increased propensity for delinquency, and emerging research on personality change suggests that mean levels of sensation seeking increase substantially from childhood to adolescence. The current study tested whether individual differences in the rate of change of sensation seeking predicted within-person change in delinquent behavior and whether genetically influenced differences in rate of personality change accounted for this association. Sensation seeking and delinquent behavior were assessed biennially between ages 10-11 and 16-17 in a nationally representative sample of 7675 youths from the National Longitudinal Study of Youth: Children and Young Adults (CNLSY). Analyses using latent growth curve modeling found that within-person change in sensation seeking was significantly and positively correlated with within-person change in delinquency from childhood to adolescence. Furthermore, behavioral genetic analyses of a subset of 2562 sibling pairs indicated that there were substantial genetic influences on both initial levels of sensation seeking and change in sensation seeking during early adolescence, with over 80% of individual differences in change due to genetic factors. Finally, these genetically driven increases in sensation seeking were most important for predicting increases in delinquency, whereas environmental paths between sensation seeking and delinquency were not significant. These results suggest that developmental changes in delinquent behaviors during adolescence are driven by a genetically governed process of personality change.
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Equitable decision making is associated with neural markers of intrinsic value
Jamil Zaki & Jason Mitchell
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
Standard economic and evolutionary models assume that humans are fundamentally selfish. On this view, any acts of prosociality - such as cooperation, giving, and other forms of altruism - result from covert attempts to avoid social injunctions against selfishness. However, even in the absence of social pressure, individuals routinely forego personal gain to share resources with others. Such anomalous giving cannot be accounted for by standard models of social behavior. Recent observations have suggested that, instead, prosocial behavior may reflect an intrinsic value placed on social ideals such as equity and charity. Here, we show that, consistent with this alternative account, making equitable interpersonal decisions engaged neural structures involved in computing subjective value, even when doing so required foregoing material resources. By contrast, making inequitable decisions produced activity in the anterior insula, a region linked to the experience of subjective disutility. Moreover, inequity-related insula response predicted individuals' unwillingness to make inequitable choices. Together, these data suggest that prosocial behavior is not simply a response to external pressure, but instead represents an intrinsic, and intrinsically social, class of reward.
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René Riedl & Andrija Javor
Journal of Neuroscience, Psychology, and Economics, forthcoming
Abstract:
Trust is among the most important factors in human life, as it pervades almost all domains of society. Although behavioral research has revealed a number of insights into the nature of trust, as well as its antecedents and consequences, an increasing number of scholars have begun to investigate the topic from a biological perspective to gain a deeper understanding. These biological investigations into trust have been carried out on three levels of analysis: genes, endocrinology, and the brain. Based on these three levels, we present a review of the literature on the biology of trust. Moreover, we integrate our findings into a conceptual framework which unifies the three levels of analysis, and we also link the biological levels to trust behavior. The results show that trust behavior is at least moderately genetically predetermined. Moreover, trust behavior is associated with specific hormones, in particular oxytocin, as well as specific brain structures, which are located in the basal ganglia, limbic system, and the frontal cortex. Based on these results, we discuss both methodological and thematic implications.
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Inner Speech during Silent Reading Reflects the Reader's Regional Accent
Ruth Filik & Emma Barber
PLoS ONE, October 2011, e25782
Abstract:
While reading silently, we often have the subjective experience of inner speech. However, there is currently little evidence regarding whether this inner voice resembles our own voice while we are speaking out loud. To investigate this issue, we compared reading behaviour of Northern and Southern English participants who have differing pronunciations for words like ‘glass', in which the vowel duration is short in a Northern accent and long in a Southern accent. Participants' eye movements were monitored while they silently read limericks in which the end words of the first two lines (e.g., glass/class) would be pronounced differently by Northern and Southern participants. The final word of the limerick (e.g., mass/sparse) then either did or did not rhyme, depending on the reader's accent. Results showed disruption to eye movement behaviour when the final word did not rhyme, determined by the reader's accent, suggesting that inner speech resembles our own voice.
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Amygdalar Function Reflects Common Individual Differences in Emotion and Pain Regulation Success
Regina Lapate et al.
Journal of Cognitive Neuroscience, January 2012, Pages 148-158
Abstract:
Although the co-occurrence of negative affect and pain is well recognized, the mechanism underlying their association is unclear. To examine whether a common self-regulatory ability impacts the experience of both emotion and pain, we integrated neuroimaging, behavioral, and physiological measures obtained from three assessments separated by substantial temporal intervals. Our results demonstrated that individual differences in emotion regulation ability, as indexed by an objective measure of emotional state, corrugator electromyography, predicted self-reported success while regulating pain. In both emotion and pain paradigms, the amygdala reflected regulatory success. Notably, we found that greater emotion regulation success was associated with greater change of amygdalar activity following pain regulation. Furthermore, individual differences in degree of amygdalar change following emotion regulation were a strong predictor of pain regulation success, as well as of the degree of amygdalar engagement following pain regulation. These findings suggest that common individual differences in emotion and pain regulatory success are reflected in a neural structure known to contribute to appraisal processes.
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Maria Groen-Blokhuis et al.
Twin Research and Human Genetics, October 2011, Pages 393-400
Abstract:
In order to estimate the influence of genetic and environmental factors on ‘crying without a cause' and ‘being easily upset' in 2-year-old children, a large twin study was carried out. Prospective data were available for ~18,000 2-year-old twin pairs from the Netherlands Twin Register. A bivariate genetic analysis was performed using structural equation modeling in the Mx software package. The influence of maternal personality characteristics and demographic and lifestyle factors was tested to identify specific risk factors that may underlie the shared environment of twins. Furthermore, it was tested whether crying without a cause and being easily upset were predictive of later internalizing, externalizing and attention problems. Crying without a cause yielded a heritability estimate of 60% in boys and girls. For easily upset, the heritability was estimated at 43% in boys and 31% in girls. The variance explained by shared environment varied between 35% and 63%. The correlation between crying without a cause and easily upset (r = .36) was explained both by genetic and shared environmental factors. Birth cohort, gestational age, socioeconomic status, parental age, parental smoking behavior and alcohol use during pregnancy did not explain the shared environmental component. Neuroticism of the mother explained a small proportion of the additive genetic, but not of the shared environmental effects for easily upset. Crying without a cause and being easily upset at age 2 were predictive of internalizing, externalizing and attention problems at age 7, with effect sizes of .28-.42. A large influence of shared environmental factors on crying without a cause and easily upset was detected. Although these effects could be specific to these items, we could not explain them by personality characteristics of the mother or by demographic and lifestyle factors, and we recognize that these effects may reflect other maternal characteristics. A substantial influence of genetic factors was found for the two items, which are predictive of later behavioral problems.
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The making of the Machiavellian brain: A structural MRI analysis
Willem Verbeke et al.
Journal of Neuroscience, Psychology, and Economics, November 2011, Pages 205-216
Abstract:
Machiavellianism is a personality style marked by the use of such tactics as deception and manipulation so as to perform well and achieve power, status, or material wealth. Based on the assumption that Machiavellians are very sensitive to status seeking in social contexts, which leads over time to changes in neuroplasticity, we hypothesize and find that salespeople who score high versus low on the Mach IV Machiavellianism scale exhibit changes in gray matter volume in the following brain regions: basal ganglia, prefrontal cortex, insula, and hippocampus. A Voxel-Based Morphometry (VBM) advanced MRI technique is used to test the hypothesis on a sample of 43 healthy salespeople. Conjectures are made on the linkage between social psychological research on Machiavellianism and neuroscience research on the brain regions in question as they relate to social behavior.
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The Neural Correlates of Empathy: Experience, Automaticity, and Prosocial Behavior
Lian Rameson, Sylvia Morelli & Matthew Lieberman
Journal of Cognitive Neuroscience, January 2012, Pages 235-245
Abstract:
Empathy is a critical aspect of human emotion that influences the behavior of individuals as well as the functioning of society. Although empathy is fundamentally a subjective experience, no studies have yet examined the neural correlates of the self-reported experience of empathy. Furthermore, although behavioral research has linked empathy to prosocial behavior, no work has yet connected empathy-related neural activity to everyday, real-world helping behavior. Lastly, the widespread assumption that empathy is an automatic experience remains largely untested. It is also unknown whether differences in trait empathy reflect either variability in the automaticity of empathic responses or the capacity to feel empathy. In this study, 32 participants completed a diary study of helping behavior followed by an fMRI session, assessing empathic responses to sad images under three conditions: watching naturally, under cognitive load, and while empathizing. Across conditions, higher levels of self-reported experienced empathy were associated with greater activity in medial PFC (MPFC). Activity in MPFC was also correlated with daily helping behavior. Self-report of empathic experience and activity in empathy-related areas, notably MPFC, were higher in the empathize condition than in the load condition, suggesting that empathy is not a fully automatic experience. Additionally, high trait empathy participants displayed greater experienced empathy and stronger MPFC responses than low trait empathy individuals under cognitive load, suggesting that empathy is more automatic for individuals high in trait empathy. These results underline the critical role that MPFC plays in the instantiation of empathic experience and consequent behavior.
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Early math achievement and functional connectivity in the fronto-parietal network
Robert Emerson & Jessica Cantlon
Developmental Cognitive Neuroscience, forthcoming
Abstract:
In this study we test the hypothesis that the functional connectivity of the frontal and parietal regions that children recruit during a basic numerical task (matching Arabic numerals to arrays of dots) is predictive of their math test scores (TEMA-3; Ginsburg, 2003). Specifically, we tested 4-11-year-old children on a matching task during fMRI to localize a fronto-parietal network that responds more strongly during numerical matching than matching faces, words, or shapes. We then tested the functional connectivity between those regions during an independent task: natural viewing of an educational video that included math topics. Using this novel natural viewing method, we found that the connectivity between frontal and parietal regions during task-independent free-viewing of educational material is correlated with children's basic number matching ability, as well as their scores on the standardized test of mathematical ability (the TEMA). The correlation between children's mathematics scores and fronto-parietal connectivity is math-specific in the sense that it is independent of children's verbal IQ scores. Moreover, a control network, selective for faces, showed no correlation with mathematics performance. Finally, brain regions that correlate with subjects' overall response times in the matching task do not account for our number- and math-related effects. We suggest that the functional intersection of number-related frontal and parietal regions is math-specific.
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Melissa Peskin et al.
Development and Psychopathology, November 2011, Pages 1059-1068
Abstract:
Although allostatic load has been investigated in mood and anxiety disorders, no prior study has investigated developmental change in allostatic load as a precursor to schizotypal personality. This study employed a multilevel developmental framework to examine whether the development of increased allostatic load, as indicated by impaired sympathetic nervous system habituation from ages 3 to 11 years, predisposes to schizotypal personality at age 23 years. Electrodermal activity to six aversive tones was recorded in 995 subjects at age 3 years and again at 11 years. Habituation slopes at both ages were used to create groups who showed a developmental increase in habituation (decreased allostatic load), and those who showed a developmental decrease in habituation (increased allostatic load). Children who showed a developmental increase in allostatic load from ages 3 to 11 years had higher levels of schizotypal personality at 23 years. A breakdown of total schizotypy scores demonstrated specificity of findings to cognitive-perceptual features of schizotypy. Findings are the first to document a developmental abnormality in allostasis in relation to adult schizotypal personality. The relative failure to develop normal habituation to repeated stressors throughout childhood is hypothesized to result in an accumulation of allostatic load and consequently increased positive symptom schizotypy in adulthood.
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Richard Wolf et al.
Neuropsychology, forthcoming
Objective: Newman and Baskin-Sommers (in press) have proposed that psychopathy reflects an attention bottleneck that interferes with processing contextual information, including the timely processing of affective and inhibitory cues that initiate self-regulation. Despite a wealth of evidence that attention moderates the affective, inhibitory, and self-regulation deficits of psychopathic offenders, to date there is little or no evidence that psychopathic offenders perform abnormally on a canonical measure of selective attention. In this study, we address this gap in the literature and clarify the attention-related abnormality in psychopathy.
Method: We administered the attentional blink (AB) task to 37 male prisoners assessed with Hare's (2003) Psychopathy Checklist-Revised. In the AB paradigm, participants identify targets in a rapid serial visual presentation. Distracters' temporal proximity to the first target elicits a conflict between attending to the target and attending to the distracters. Greater conflict results in a larger AB (i.e., reduced accuracy for the second target).
Results: As predicted, psychopathic offenders displayed a significantly smaller AB (i.e., better accuracy throughout the blink interval) than nonpsychopathic offenders.
Conclusions: Consistent with the attentional bottleneck hypothesis, psychopathic participants were less susceptible to distracter effects following presentation of an initial target. The results clarify the nature of the attention bottleneck in psychopathy, the circumstances in which it enhances versus interferes with performance, and its implications for more ecologically valid conditions involving the sequential presentation of goal-relevant and goal-incongruent information.
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Breakdown in the brain network subserving moral judgment in criminal psychopathy
Jesus Pujol et al.
Social Cognitive and Affective Neuroscience, forthcoming
Abstract:
Neuroimaging research has demonstrated the involvement of a well-defined brain network in the mediation of moral judgment in normal population, and has suggested the inappropriate network use in criminal psychopathy. We used functional magnetic resonance imaging (fMRI) to prove that alterations in the brain network subserving moral judgment in criminal psychopaths are not limited to the inadequate network use during moral judgment, but that a primary network breakdown would exist with dysfunctional alterations outside moral dilemma situations. A total of 22 criminal psychopathic men and 22 control subjects were assessed and fMRI maps were generated to identify (i) brain response to moral dilemmas, (ii) task-induced deactivation of the network during a conventional cognitive task and (iii) the strength of functional connectivity within the network during resting-state. The obtained functional brain maps indeed confirmed that the network subserving moral judgment is underactive in psychopathic individuals during moral dilemma situations, but the data also provided evidence of a baseline network alteration outside moral contexts with a functional disconnection between emotional and cognitive elements that jointly construct moral judgment. The finding may have significant social implications if considering psychopathic behavior to be a result of a primary breakdown in basic brain systems.