We investigate the hypothesis that those subregions of the prefrontal cortex (PFC) found to support proactive interference resolution may also support delay-spanning distractor interference resolution. Ten subjects performed delayed-recognition tasks requiring working memory for faces or shoes during functional MRI scanning. During the 15-sec delay interval, task-irrelevant distractors were presented. These distractors were either all faces or all shoes and were thus either congruent or incongruent with the domain of items in the working memory task. Delayed-recognition performance was slower and less accurate during congruent than during incongruent trials. Our fMRI analyses revealed significant delay interval activity for face and shoe working memory tasks within both dorsal and ventral PFC. However, only ventral PFC activity was modulated by distractor category, with greater activity for congruent than for incongruent trials. Importantly, this congruency effect was only present for correct trials. In addition to PFC, activity within the fusiform face area was investigated. During face distraction, activity was greater for face relative to shoe working memory. As in ventrolateral PFC, this congruency effect was only present for correct trials. These results suggest that the ventrolateral PFC and fusiform face area may work together to support delay-spanning interference resolution.
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Drawing on recent claims in the study of relationships, attachment, and emotion, the authors hypothesized that romantic love serves a commitment-related function and sexual desire a reproduction-related function. Consistent with these claims, in Study 1, brief experiences of romantic love and sexual desire observed in a 3-min interaction between romantic partners were related to distinct feeling states, distinct nonverbal displays, and commitment- and reproductive-related relationship outcomes, respectively. In Study 2, the nonverbal display of romantic love was related to the release of oxytocin. Discussion focuses on the place of romantic love and sexual desire in the literature on emotion.
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This study, based on a sample of 172 children, examined the relation between average afternoon salivary cortisol levels measured at home at age 4.5 years and socioemotional adjustment a year and a half later, as reported by mothers, fathers, and teachers. Cortisol levels were hypothesized to be positively associated with withdrawal-type behaviors (e.g., internalizing, social wariness) and inversely related to approach-type behaviors, both negative and positive (e.g., externalizing, school engagement). Higher cortisol levels at age 4.5 predicted more internalizing behavior and social wariness as reported by teachers and mothers, although child gender moderated the relation between cortisol and mother report measures. An inverse relation was found between boys' cortisol levels and father report of externalizing behavior. A marginal inverse relation was found between child cortisol levels and teacher report of school engagement. Behavior assessed concurrently with cortisol collection did not account for the prospective relations observed,suggesting that cortisol adds uniquely to an understanding of behavioral development.
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Selective attention has been shown to bias sensory processing in favor of relevant stimuli and against irrelevant or distracting stimuli in perceptual tasks. Increasing evidence suggests that selective attention plays an important role during working memory maintenance, possibly by biasing sensory processing in favor of to-be-remembered items. In the current study, we investigated whether selective attention may also support working memory by biasing processing against irrelevant and potentially distracting information. Event-related potentials (ERPs) were recorded while subjects (n = 22) performed a delayed-recognition task for faces and shoes. The delay period was filled with face or shoe distractors. Behavioral performance was impaired when distractors were congruent with the working memory domain (e.g., face distractor during working memory for faces) relative to when distractors were incongruent with the working memory domain (e.g., face distractor during shoe working memory). If attentional biasing against distractor processing is indeed functionally relevant in supporting working memory maintenance, perceptual processing of distractors is predicted to be attenuated when distractors are more behaviorally intrusive relative to when they are nonintrusive. As such, we predicted that perceptual processing of distracting faces, as measured by the face-sensitive N170 ERP component, would be reduced in the context of congruent (face) working memory relative to incongruent (shoe) working memory. The N170 elicited by distracting faces demonstrated reduced amplitude during congruent versus incongruent working memory. These results suggest that perceptual processing of distracting faces may be attenuated due to attentional biasing against sensory processing of distractors that are most behaviorally intrusive during working memory maintenance.
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The serotonin transporter (5-HTT) plays a critical role in regulating serotonergic neurotransmission and is implicated in the pathophysiology of anxiety and affective disorders. Positron emission tomography scans using [(11)C]DASB [(11)C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile] to measure 5-HTT availability (an index of receptor density and binding) were performed in 34 rhesus monkeys in which the relationship between regional brain glucose metabolism and anxious temperament was previously established. 5-HTT availability in the amygdalohippocampal area and bed nucleus of the stria terminalis correlated positively with individual differences in a behavioral and neuroendocrine composite of anxious temperament. 5-HTT availability also correlated positively with stress-induced metabolic activity within these regions. Collectively, these findings suggest that serotonergic modulation of neuronal excitability in the neural circuitry associated with anxiety mediates the developmental risk for affect-related psychopathology.
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The length polymorphism of the serotonin (5-HT) transporter gene promoter region has been implicated in altered 5-HT function and, in turn, neuropsychiatric illnesses, such as anxiety and depression. The nonhuman primate has been used as a model to study anxiety-related mechanisms in humans based upon similarities in behavior and the presence of a similar 5-HT transporter gene polymorphism. Stressful and threatening contexts in the nonhuman primate model have revealed 5-HT transporter genotype dependent differences in regional glucose metabolism. Using the rhesus monkey, we examined the extent to which serotonin transporter genotype is associated with 5-HT transporter binding in brain regions implicated in emotion-related pathology.
METHODS: Genotype data and high resolution PET scans were acquired in 29 rhesus (Macaca mulatta) monkeys. [C-11]DASB dynamic PET scans were acquired for 90 min in the anesthetized animals and images of distribution volume ratio (DVR) were created to serve as a metric of 5-HT transporter binding for group comparison based on a reference region method of analysis. Regional and voxelwise statistical analysis were performed with corrections for anatomical differences in gray matter probability, sex, age and radioligand mass.
RESULTS: There were no significant differences when comparing l/l homozygotes with s-carriers in the regions of the brain implicated in anxiety and mood related illnesses (amygdala, striatum, thalamus, raphe nuclei, temporal and prefrontal cortex). There was a significant sex difference in 5-HT transporter binding in all regions with females having 18%-28% higher DVR than males.
CONCLUSIONS: Because these findings are consistent with similar genotype findings in humans, this further strengthens the use of the rhesus model for studying anxiety-related neuropathologies.
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A variant allele in the promoter region of the serotonin transporter gene, SLC6A4, the s allele, is associated with increased vulnerability to develop anxiety-related traits and depression. Furthermore, functional magnetic resonance imaging (fMRI) studies reveal that s carriers have increased amygdala reactivity in response to aversive stimuli, which is thought to be an intermediate phenotype mediating the influences of the s allele on emotionality. We used high-resolution microPET [18F]fluoro-2-deoxy-D-glucose (FDG) scanning to assess regional brain metabolic activity in rhesus monkeys to further explore s allele-related intermediate phenotypes. Rhesus monkeys provide an excellent model to understand mechanisms underlying human anxiety, and FDG microPET allows for the assessment of brain activity associated with naturalistic environments outside the scanner. During FDG uptake, monkeys were exposed to different ethologically relevant stressful situations (relocation and threat) as well as to the less stressful familiar environment of their home cage. The s carriers displayed increased orbitofrontal cortex activity in response to both relocation and threat. However, during relocation they displayed increased amygdala reactivity and in response to threat they displayed increased reactivity of the bed nucleus of the stria terminalis. No increase in the activity of any of these regions occurred when the animals were administered FDG in their home cages. These findings demonstrate context-dependent intermediate phenotypes in s carriers that provide a framework for understanding the mechanisms underlying the vulnerabilities of s-allele carriers exposed to different types of stressors.
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This paper reports three studies showing sex differences in EEG asymmetry during self-generated cognitive and affective tasks. In the first experiment, bilateral EEG, quantified for alpha on-line, was recorded from right-handed subjects while they either whistled, sang or recited lyrics of familiar songs. The results revealed significant asymmetry between the whistle and talk conditions only for subjects with no familial left-handedness and, within this group, only for females and not for males. In the second experiment, bilateral EEG was recorded while right-handed subjects (with no familial left-handedness) self-induced covert affective and non-affective states. Results revealed significantly greater relative right-hemisphere activation during emotion versus non-emotion trials only in females; males showed no significant task-dependent shifts in asymmetry between conditions. The third experiment was designed to test the hypothesis that females show greater percent time asymmetry than males during biofeedback training for symmetrical and asymmetrical EEG patterns. Results confirmed this prediction as well as indicating that females show better control of such asymmetrical cortical patterning. These findings provide new neuropsychological support for the hypothesis of greater bilateral flexibility in females during self-generation tasks.
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The development of functional neuroimaging of emotion holds the promise to enhance our understanding of the biological bases of affect and improve our knowledge of psychiatric diseases. However, up to this point, researchers have been unable to objectively, continuously and unobtrusively measure the intensity and dynamics of affect concurrently with functional magnetic resonance imaging (fMRI). This has hindered the development and generalizability of our field. Facial electromyography (EMG) is an objective, reliable, valid, sensitive, and unobtrusive measure of emotion. Here, we report the successful development of a method for simultaneously acquiring fMRI and facial EMG. The ability to simultaneously acquire brain activity and facial physiology will allow affective neuroscientists to address theoretical, psychiatric, and individual difference questions in a more rigorous and generalizable way.
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Test-retest reliability of resting regional cerebral metabolic rate of glucose (rCMR) was examined in selected subcortical structures: the amygdala, hippocampus, thalamus, and anterior caudate nucleus. Findings from previous studies examining reliability of rCMR suggest that rCMR in small subcortical structures may be more variable than in larger cortical regions. We chose to study these subcortical regions because of their particular interest to our laboratory in its investigations of the neurocircuitry of emotion and depression. Twelve normal subjects (seven female, mean age = 32.42 years, range 21-48 years) underwent two FDG-PET scans separated by approximately 6 months (mean = 25 weeks, range 17-35 weeks). A region-of-interest approach with PET-MRI coregistration was used for analysis of rCMR reliability. Good test-retest reliability was found in the left amygdala, right and left hippocampus, right and left thalamus, and right and left anterior caudate nucleus. However, rCMR in the right amygdala did not show good test-retest reliability. The implications of these data and their import for studies that include a repeat-test design are considered.
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Recent evidence suggests that perceptions of social class rank influence a variety of social cognitive tendencies, from patterns of causal attribution to moral judgment. In the present studies we tested the hypotheses that upper-class rank individuals would be more likely to endorse essentialist lay theories of social class categories (i.e., that social class is founded in genetically based, biological differences) than would lower-class rank individuals and that these beliefs would decrease support for restorative justice--which seeks to rehabilitate offenders, rather than punish unlawful action. Across studies, higher social class rank was associated with increased essentialism of social class categories (Studies 1, 2, and 4) and decreased support for restorative justice (Study 4). Moreover, manipulated essentialist beliefs decreased preferences for restorative justice (Study 3), and the association between social class rank and class-based essentialist theories was explained by the tendency to endorse beliefs in a just world (Study 2). Implications for how class-based essentialist beliefs potentially constrain social opportunity and mobility are discussed.
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Power increases the tendency to behave in a goal-congruent fashion. Guided by this theoretical notion, we hypothesized that elevated power would strengthen the positive association between prosocial orientation and empathic accuracy. In 3 studies with university and adult samples, prosocial orientation was more strongly associated with empathic accuracy when distinct forms of power were high than when power was low. In Study 1, a physiological indicator of prosocial orientation, respiratory sinus arrhythmia, exhibited a stronger positive association with empathic accuracy in a face-to-face interaction among dispositionally high-power individuals. In Study 2, experimentally induced prosocial orientation increased the ability to accurately judge the emotions of a stranger but only for individuals induced to feel powerful. In Study 3, a trait measure of prosocial orientation was more strongly related to scores on a standard test of empathic accuracy among employees who occupied high-power positions within an organization. Study 3 further showed a mediated relationship between prosocial orientation and career satisfaction through empathic accuracy among employees in high-power positions but not among employees in lower power positions. Discussion concentrates upon the implications of these findings for studies of prosociality, power, and social behavior.
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<p>Social cognition, including complex social judgments and attitudes, is shaped by individual learning experiences, where affect often plays a critical role. Aversive classical conditioning-a form of associative learning involving a relationship between a neutral event (conditioned stimulus, CS) and an aversive event (unconditioned stimulus, US)-represents a well-controlled paradigm to study how the acquisition of socially relevant knowledge influences behavior and the brain. Unraveling the temporal unfolding of brain mechanisms involved appears critical for an initial understanding about how social cognition operates. Here, 128-channel ERPs were recorded in 50 subjects during the acquisition phase of a differential aversive classical conditioning paradigm. The CS+ (two fearful faces) were paired 50% of the time with an aversive noise (CS upward arrow + /Paired), whereas in the remaining 50% they were not (CS upward arrow + /Unpaired); the CS- (two different fearful faces) were never paired with the noise. Scalp ERP analyses revealed differences between CS upward arrow + /Unpaired and CS- as early as approximately 120 ms post-stimulus. Tomographic source localization analyses revealed early activation modulated by the CS+ in the ventral visual pathway (e.g. fusiform gyrus, approximately 120 ms), right middle frontal gyrus (approximately 176 ms), and precuneus (approximately 240 ms). At approximately 120 ms, the CS- elicited increased activation in the left insula and left middle frontal gyrus. These findings not only confirm a critical role of prefrontal, insular, and precuneus regions in aversive conditioning, but they also suggest that biologically and socially salient information modulates activation at early stages of the information processing flow, and thus furnish initial insight about how affect and social judgments operate.</p>
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We used fMRI to examine amygdala activation in response to fearful facial expressions, measured over multiple scanning sessions. 15 human subjects underwent three scanning sessions, at 0, 2 and 8 weeks. During each session, functional brain images centered about the amygdala were acquired continuously while participants were shown alternating blocks of fearful, neutral and happy facial expressions. Intraclass correlation coefficients calculated across the sessions indicated stability of response in left amygdala to fearful faces (as a change from baseline), but considerably less left amygdala stability in responses to neutral expressions and for fear versus neutral contrasts. The results demonstrate that the measurement of fMRI BOLD responses in amygdala to fearful facial expressions might be usefully employed as an index of amygdala reactivity over extended periods. While signal change to fearful facial expressions appears robust, the experimental design employed here has yielded variable responsivity within baseline or comparison conditions. Future studies might manipulate the experimental design to either amplify or attenuate this variability, according to the goals of the research.
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The present study was undertaken to determine whether aversiveness contributes to startle potentiation in anticipation of affective pictures above and beyond the effects of emotional arousal. Further, participants high in trait anxious apprehension, which is characterized by worry about the future, were expected to show especially pronounced anticipatory startle responses. Startle blink reflex was measured during warning stimuli that predicted the valence of ensuing aversive/unpleasant, pleasant, or neutral pictures. Startle magnitude was larger in anticipation of aversive than of pleasant pictures and smallest in anticipation of neutral pictures. Enhanced startle potentiation was not found in anxious apprehension subjects. These data suggest that the aversive nature of stimuli contribute to the potentiation of startle above and beyond the effects of emotional arousal, which may be a universal phenomenon not modulated by individual differences.
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<p>Previous research has reported that individuals high in the need for Power, high in inhibition, and high in power stress (the HHH group) are more likely than other individuals to report more severe illnesses. The present study investigates the possibility that the mechanism underlying this relationship is greater sympathetic activation in the HHH group which has an immunosuppressive effect. College males with the HHH syndrome reported more frequent and more severe illnesses than other individuals, as in previous studies. More of the HHH than other subjects also showed above average epinephrine excretion rates in urine and below average concentrations of immunoglobulin A in saliva (S-IgA). Furthermore, higher rates of epinephrine excretion were significantly associated with lower S-IgA concentrations, and lower S-IgA concentrations were significantly associated with reports of more frequent illnesses. The findings are interpreted as consistent with the hypothesis that a strong need for Power, if it is inhibited and stressed, leads to chronic sympathetic overactivity which has an immunosuppressive effect making individuals characterized by this syndrome more susceptible to illness.</p>
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Laughter facilitates the adaptive response to stress by increasing the psychological distance from distress and by enhancing social relations. To test these hypotheses, the authors related measures of bereaved adults' laughter and smiling 6 months postloss to measures of their (a) subjective emotion and dissociation from distress, (b) social relations, and (c) responses they evoked in others. Duchenne laughter, which involves orbicularis oculi muscle action, related to self-reports of reduced anger and increased enjoyment, the dissociation of distress, better social relations, and positive responses from strangers, whereas non-Duchenne laughter did not. Lending credence to speculations in the ethological literature, Duchenne laughter correlated with different intrapersonal and interpersonal responses than Duchenne smiles. Discussion focuses on the relevance of these findings to theories of positive emotion.
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BACKGROUND: Hypothalamic-pituitary-adrenal (HPA) system activation is adaptive in response to stress, and HPA dysregulation occurs in stress-related psychopathology. It is important to understand the mechanisms that modulate HPA output, yet few studies have addressed the neural circuitry associated with HPA regulation in primates and humans. Using high-resolution F-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in rhesus monkeys, we assessed the relation between individual differences in brain activity and HPA function across multiple contexts that varied in stressfulness.
METHODS: Using a logical AND conjunctions analysis, we assessed cortisol and brain metabolic activity with FDG-PET in 35 adolescent rhesus monkeys exposed to two threat and two home-cage conditions. To test the robustness of our findings, we used similar methods in an archival data set. In this data set, brain metabolic activity and cortisol were assessed in 17 adolescent male rhesus monkeys that were exposed to three stress-related contexts.
RESULTS: Results from the two studies revealed that subgenual prefrontal cortex (PFC) metabolism (Brodmann's area 25/24) consistently predicted individual differences in plasma cortisol concentrations regardless of the context in which brain activity and cortisol were assessed.
CONCLUSIONS: These findings suggest that activation in subgenual PFC may be related to HPA output across a variety of contexts (including familiar settings and novel or threatening situations). Individuals prone to elevated subgenual PFC activity across multiple contexts may be individuals who consistently show heightened cortisol and may be at risk for stress-related HPA dysregulation.
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Despite the prominence of emotional dysfunction in psychopathology, relatively few experiments have explicitly studied emotion regulation in adults. The present study examined one type of emotion regulation: voluntary regulation of short-term emotional responses to unpleasant visual stimuli. In a sample of 48 college students, both eyeblink startle magnitude and corrugator activity were sensitive to experimental manipulation. Instructions to suppress negative emotion led to both smaller startle eyeblinks and decreased corrugator activity. Instructions to enhance negative emotion led to larger startle eyeblinks and increased corrugator activity. Several advantages of this experimental manipulation are discussed, including the use of both a suppress and an enhance emotion condition, independent measurement of initial emotion elicitation and subsequent regulation of that emotion, the use of a completely within-subjects design, and the use of naturalistic emotion regulation strategies.
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What happens when people suppress their emotions when they sacrifice for a romantic partner? This multimethod study investigates how suppressing emotions during sacrifice shapes affective and relationship outcomes. In Part 1, dating couples came into the laboratory to discuss important romantic relationship sacrifices. Suppressing emotions was associated with emotional costs for the partner discussing his or her sacrifice. In Part 2, couples participated in a 14-day daily experience study. Within-person increases in emotional suppression during daily sacrifice were associated with decreases in emotional well-being and relationship quality as reported by both members of romantic dyads. In Part 3, suppression predicted decreases in relationship satisfaction and increases in thoughts about breaking up with a romantic partner 3 months later. In the first two parts of the study, authenticity mediated the costly effects of suppression. Implications for research on close relationships and emotion regulation are discussed.
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Tactile communication, or physical touch, promotes cooperation between people, communicates distinct emotions, soothes in times of stress, and is used to make inferences of warmth and trust. Based on this conceptual analysis, we predicted that in group competition, physical touch would predict increases in both individual and group performance. In an ethological study, we coded the touch behavior of players from the National Basketball Association (NBA) during the 2008-2009 regular season. Consistent with hypotheses, early season touch predicted greater performance for individuals as well as teams later in the season. Additional analyses confirmed that touch predicted improved performance even after accounting for player status, preseason expectations, and early season performance. Moreover, coded cooperative behaviors between teammates explained the association between touch and team performance. Discussion focused on the contributions touch makes to cooperative groups and the potential implications for other group settings.
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<p>Recent evidence suggests that frontal brain electrical activity reveals asymmetries in activation in response to positive vs negative affective stimuli. This study was designed to evaluate whether this asymmetry is present at birth. Newborn infants were presented with water followed by a sucrose solution and then by a citric acid solution. Facial expression was videotaped during the presentation of the liquids and EEG was recorded from the frontal and parietal scalp regions on the left and right side. Usable EEG data were obtained from 16 newborn infants in response to these taste conditions. Videotaping of facial expression in response to these stimuli indicated the presence of disgust during both water (the first taste introduced) and citric acid. EEG was Fourier Transformed and power in the 1-3, 3-6 and 6-12 Hz bands was computed. The findings revealed that the water condition produced reductions in right-hemisphere power in the two higher frequency bands in both the scalp regions compared with the other two conditions. The sucrose condition produced greater relative left-sided activation in both regions compared with the water condition. These data, in conjunction with our previous findings of asymmetries in 10-month-old infants, indicate that stimulus-elicited affective asymmetries in brain electrical activity are present at birth.</p>
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Following E. Goffman's (1967) face threat analysis of social interaction, it was hypothesized that the aggressive, playful content of teasing would vary according to social status and relational satisfaction, personality, role as teaser or target, and gender. These 4 hypotheses were tested in analyses of the teasing among fraternity members (Study 1) and romantic couples (Study 2). Consistent with a face threat analysis of teasing, low-status fraternity members and satisfied romantic partners teased in more prosocial ways, defined by reduced face threat and increased redressive action. Some findings indicate that disagreeable individuals teased in less prosocial ways, consistent with studies of bullying. Targets reported more negative emotion than teasers. Although female and male romantic partners teased each other in similar ways, women found being the target of teasing more aversive, consistent with previous speculation.
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Although tantrums are among the most common behavioral problems of young children and may predict future antisocial behavior, little is known about them. To develop a model of this important phenomenon of early childhood, behaviors reported in parental narratives of the tantrums of 335 children aged 18 to 60 months were encoded as present or absent in consecutive 30-second periods. Principal Component (PC) analysis identified Anger and Distress as major, independent emotional and behavioral tantrum constituents. Anger-related behaviors formed PCs at three levels of intensity. High-intensity anger decreased with age, and low-intensity anger increased. Distress, the fourth PC, consisted of whining, crying, and comfort-seeking. Coping Style, the fifth PC, had high but opposite loadings on dropping down and running away, possibly reflecting the tendency to either "submit" or "escape." Model validity was indicated by significant correlations of the PCs with tantrum variables that were, by design, not included in the PC analysis.
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This article completes the analysis of parental narratives of tantrums had by 335 children aged 18 to 60 months. Modal tantrum durations were 0.5 to 1 minute; 75% of the tantrums lasted 5 minutes or less. If the child stamped or dropped to the floor in the first 30 seconds, the tantrum was likely to be shorter and the likelihood of parental intervention less. A novel analysis of behavior probabilities that permitted grouping of tantrums of different durations converged with our previous statistically independent results to yield a model of tantrums as the expression of two independent but partially overlapping emotional and behavioral processes: Anger and Distress. Anger rises quickly, has its peak at or near the beginning of the tantrum, and declines thereafter. Crying and comfort-seeking, components of Distress, slowly increase in probability across the tantrum. This model indicates that tantrums can provide a window on the intense emotional processes of childhood.
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