Infidelity, race, and gender: An evolutionary perspective on asymmetries in subjective distress to violations-of-trust

Asymmetries in subjective distress were observed among African American and white (N = 191) men and women who were asked to imagine a partner being emotionally and sexually unfaithful, and a partner committing other paired, gender-linked viola-tions-of-trust. More women than men were distressed by imagining a partner forming a deep emotional attachment to another person and more men than women were distressed by imagining a partner enjoying passionate sexual intercourse with another person. In addition, more men than women were distressed by male-linked violations, such as a partner no longer trying to look attractive, and more women than men were distressed by female-linked violations, such as a partner no longer wanting to work. The results contribute to a growing body of cross-cultural research reporting gender differences in distress to emotional and sexual infidelity. The results also provide cross-cultural validation of the extension of an evolutionary perspective to under-standing gender differences in subjective distress to other biologically relevant viola-tions-of-trust.     

Infidelity, race, and gender: An evolutionary perspective on asymmetries in subjective distress to violations-of-trust

Asymmetries in subjective distress were observed among African American and white (N = 191) men and women who were asked to imagine a partner being emotionally and sexually unfaithful, and a partner committing other paired, gender-linked viola-tions-of-trust. More women than men were distressed by imagining a partner forming a deep emotional attachment to another person and more men than women were distressed by imagining a partner enjoying passionate sexual intercourse with another person. In addition, more men than women were distressed by male-linked violations, such as a partner no longer trying to look attractive, and more women than men were distressed by female-linked violations, such as a partner no longer wanting to work. The results contribute to a growing body of cross-cultural research reporting gender differences in distress to emotional and sexual infidelity. The results also provide cross-cultural validation of the extension of an evolutionary perspective to under-standing gender differences in subjective distress to other biologically relevant viola-tions-of-trust.     

Emotional and hemispheric asymmetries in shifts of attention: An ERP study

Inhibition of return (IOR) refers to the larger response time to cued targets appearing at long cue-to-target intervals. Given emotion–attention interactions and associated visual field (VF) asymmetries, we examined the effects of emotions and hemispheric processing on object- and location-based IOR. We expected reduced IOR and right hemispheric bias accompanied by differences in event-related potentials (ERPs) including lack of suppression of cued N1 and enhancement of Nd components for sad targets. Reaction times and ERPs were recorded in an exogenous cuing detection task using happy and sad schematic faces. Results revealed reduced IOR for left compared to right VF with sad faces but no such asymmetry for happy faces. Cued N1 amplitudes were suppressed for happy targets but not for sad targets presented to the left VF. Nd amplitudes were enhanced for right-hemispheric sad faces especially with object-based IOR. The results indicate right-hemispheric advantage in the capture of attention by negative emotion especially with object-based selection.     

Emotional valence and arousal effects on memory and hemispheric asymmetries

This study examined predictions based upon the right hemisphere (RH) model, the valence–arousal model, and a recently proposed integrated model (Killgore & Yurgelun-Todd, 2007) of emotion processing by testing immediate recall and recognition memory for positive, negative, and neutral verbal stimuli among 35 right-handed women. Building upon methodologies of previous studies, we found that words presented to the right visual field/left hemisphere (RVF/LH) were recalled and recognized more accurately than words presented to the left visual field/right hemisphere (LVF/RH), and we found significant valence by visual field interactions. Some findings were consistent with one of the models evaluated whereas others were consistent with none of the models evaluated. Our findings suggest that an integration of the RH and valence–arousal models may best account for the findings with regard to hemispheric lateralization of memory for emotional stimuli.     

The cost of action miscues: hemispheric asymmetries

Adaptive behaviors require preparation and when necessary inhibition or alteration of actions. The right hemisphere has been posited to be dominant for preparatory motor activation. This experiment was designed to learn if there are hemispheric asymmetries in the control of altered plans of actions. Cues, both valid and invalid, which indicate the hand most likely to be called onto respond, as well as the imperative stimuli that indicate the actual response hand, were presented to either the right or left visual fields of 14 normal right handed participants. The delay after a miscue is dependent on the time taken to inhibit the premotor and motor systems of the incorrectly activated hemisphere, as well as to activate the motor systems of the opposite hemisphere, which might have been interhemispherically inhibited by this miscue. Analyses of reaction times revealed that miscues presented in left hemispace (right hemisphere) cost more time than those miscues presented in right hemispace (left hemisphere), suggesting that activation of the preparatory systems controlled by the right hemisphere may take longer to reverse than those controlled by the left hemisphere. This asymmetry may be related to asymmetries in the strength of hemispheric activation with contralateral inhibition.     

Visual hemispheric asymmetries depend on which spatial frequencies are task relevant

Observers classified sine-wave and square-wave gratings on the basis of fundamental frequency (Are the bars wide or narrow?) or on the basis of higher harmonic frequencies (Are the bars sharp or fuzzy?). Stimuli were presented in either the left (LVF) or right (RVF) visual field. When the classification was made on the basis of the fundamental frequencies (1 or 3 c/deg), there was a LVF/right hemisphere advantage. However, when the classification was on the basis of a sharp/fuzzy distinction which involved searching for the higher harmonic frequencies, then a RVF/left hemisphere advantage was found.     

Effect of temporal constraints on hemispheric asymmetries during spatial frequency processing

Studies on functional hemispheric asymmetries have suggested that the right vs. left hemisphere should be predominantly involved in low vs. high spatial frequency (SF) analysis, respectively. By manipulating exposure duration of filtered natural scene images, we examined whether the temporal characteristics of SF analysis (i.e., the temporal precedence of low on high spatial frequencies) may interfere with hemispheric specialization. Results showed the classical hemispheric specialization pattern for brief exposure duration and a trend to a right hemisphere advantage irrespective of the SF content for longer exposure duration. The present study suggests that the hemispheric specialization pattern for visual information processing should be considered as a dynamic system, wherein the superiority of one hemisphere over the other could change according to the level of temporal constraints: the higher the temporal constraints of the task, the more the hemispheres are specialized in SF processing.     

Effects of a concurrent memory task on hemispheric asymmetries in categorization

Recent research on the division of processing between the two cerebral hemispheres has often employed two concurrent tasks to investigate the dynamic nature of hemispheric asymmetries. The experiment reported here explored the effects of two concurrent high-level cognitive tasks (memory retention and semantic categorization) on the direction and magnitude of hemispheric differences in the processing of words and pictures. Subjects were required to categorize words and pictures presented to either the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH). The categorization could be performed while holding either verbal material in memory (digit span), pictorial material in memory (serial nonsense figure recognition), or with no concurrent memory task. The effects produced hemisphere-specific, material-nonspecific interference. The verbal task removed a RVF-LH advantage at word categorization and enhanced a LVF-RH advantage on picture categorization; the pictorial task interfered with picture categorization in the LVF-RH, while enhancing a RVF-LH advantage at word categorization. The results are discussed in terms of multiple resource models of hemisphere function, capacity limitations, and the functional locus of processing required to produce various dynamic hemispheric effects.     

Unilateral hemispheric activation does not affect free-viewing perceptual asymmetries

Strong leftward perceptual biases have been reported for the selection of the darker of two left/right mirror-reversed luminance gradients under free-viewing conditions. This study investigated the effect of unilateral hemispheric activation on this leftward bias in two groups of dextrals (N = 52 and N = 24). In Experiment 1, activation was manipulated by asking participants to tap with their left or right fingers along their midline. In Experiment 2, participants clenched their left or right hands in their respective hemispaces. Participants selected the stimulus that was darker on the left-hand side 73% of the time. Despite manipulations of activation strength and hemispace, activation had no effect on the asymmetry. If activation was important, the leftward bias should have been enhanced when the left hand/right hemisphere was active and reduced (or reversed) when the right hand/left hemisphere was active. The contribution of left-to-right scanning biases to free-viewing perceptual asymmetries is discussed as an alternative.     

An evolutionary perspective on effective vs. ineffective pick-up lines

This experiment examined women's impressions of men using various "pick-up" lines. Seventy women imagined being approached by a man using a flippant and flirtatious "pick-up" line, a direct complimentary line, or an innocuous line that masks his interest. His attractiveness varied too. They then considered him for long-term or short-term relationships. Matching a "good dad" hypothesis, they favored him for a long-term relationship if he used a direct or innocuous line instead of the flippant line, because the latter conveyed lower trustworthiness and intelligence. Matching a "good genes" hypothesis, they favored him for a short-term relationship if he was attractive instead of unattractive, regardless of his pick-up line, presumably because attractiveness signals heritable fitness. Limitations and theoretical implications are discussed.     

A novel contact-lens system to assess visual hemispheric asymmetries.

A soft contact-lens system for achieving unilateral visual stimulation in a free vision format is described. Initial testing with light transmittance and visual perimetry indicated that the lenses created artificial visual-field deficits. The efficacy of the lenses as a technique for lateralizing visual input was evaluated by examining within-subject differences in performance on two visuospatial tasks. Speed and accuracy of performance were greater with visual input directed to the right hemisphere. These data support the lens design as a useful alternative to tachistoscopic procedures and previous lens systems.     

Context modulates hemispheric asymmetries in the resolution of lexical ambiguity

Previous studies have reported a hemispheric asymmetry in processing dominant (e.g., paper) and subordinate (e.g., farmer) associations of ambiguous words (e.g., pen). The majority of these studies, however, applied randomly ordered presentation and collected right-hand responses only. Generating responses solely with the right hand and the randomly ordered presentation of association type might have affected natural hemispheric expertise. We explored the putative relationships between responding hand and experimental design manipulations in processing lexical ambiguity. Ambiguous target words were laterally presented following word pairs that could be associated to the dominant or subordinate meaning of the target word. We manipulated the responding hand and the experimental context by presenting the semantic associations in a random (Experiment 1) and a blocked ordered presentation (Experiment 2). The results of Experiment 2 supported the right hemisphere expertise hypothesis, whereas the results of Experiment 1 can be best explained by the direct access model where stimuli are processed by the hemisphere receiving them first, without relying on hemispheric expertise. We conclude that without manipulating the responding hand, there is a risk of misinterpreting direct access results as evidence for hemispheric expertise. Moreover, we suggest that a blocked ordered presentation might encourage participants to use the expert hemisphere for the blocked factor. A new theoretical framework is presented to explain the findings.     

The effect of response competition on functional hemispheric asymmetries for global/local processing

It is widely assumed that the cerebral hemispheres differ in their capacity for processing the global and local levels of hierarchical stimuli. However, corresponding visual-field (VF) effects in response time studies did not show up under all circumstances. In the present article the role of response conflict between the levels for the occurrence of these effects is investigated. Three experiments with hierarchical letters are reported, in which the absolute and/or the relative interference between the stimulus levels was varied. It turned out that VF effects occurred only for conflicting stimuli and only when there was at least a certain amount of absolute interference, whereas variations of the relative interference had no effect in this respect. These results suggest that there is a qualitative relationship between interference and VF effects. A possible explanation is provided by the assumption that the hemispheres are functionally equivalent with respect to early stimulus representations, whereas they differ in their efficiency for integrating letter identity and stimulus level.     

An evolutionary psychology perspective on sex differences in exercise behaviors and motivations

Researchers have found that men and women pursue sex-appropriate strategies to attract mates. On the basis of intrasexual competition, men should be more likely to enact behaviors to look larger, whereas women should be more likely to enact behaviors to look smaller. The types of exercises that each performs should reflect this expectation. The present study replicates and extends work by L. Mealey (1997) on sex differences in exercise behavior. In the present study, male participants focused their energy on gaining muscle mass and enhancing their upper body definition, whereas female participants focused their energy on losing weight with emphasis on their lower body. Both sexes reported efforts to improve their abdominal region. It appears that men and women adopt sex-appropriate exercise behavior as a method of self-enhancement for intrasexual competition.     

Structural influences on the resolution of lexical ambiguity: an analysis of hemispheric asymmetries

Structural influences on lexical ambiguity resolution in the two cerebral hemispheres was investigated using a divided visual field procedure. Participants were presented with auditory Wh- sentences containing an ambiguous word, where the grammatical role of the word was apparent only at a sentence-final verb (e.g., "Which BANK did the woman see?"). Following a sentence, either immediately or after 600 ms, a target word was presented in either the right or left visual field. Targets were related to the ambiguous word's dominant meaning (MONEY), the subordinate meaning (RIVER), or were unrelated. With left visual field presentation, priming occurred for both dominant- and subordinate-related targets at a 0 ms delay, but only for dominant-related targets at 600 ms. With left visual field presentation, priming occurred for subordinate-related targets only at both delays. The results suggest that grammatical assignment triggers the selection of meaning in the left hemisphere, whereas processing in the right hemisphere operates independently of structural analyses.     

面孔吸引力和配偶价值:进化心理学视角

面孔吸引力是对个体容貌的审美评价。根据进化心理学的观点,面孔吸引力是配偶价值的线索。这一假设是进化心理学视角下的面孔吸引力研究的前提所在。本文就涉及这一核心假设的研究进行梳理,重点关注影响面孔吸引力的形态特征与配偶价值的关系。这些形态特征包括面孔的性别二态性特征,面孔的波动性不对称特征以及面孔的肥胖特征。     

The roles of stimulus repetition and hemispheric activation in visual half-field asymmetries

Hardyck, Tzeng, and Wang (1978, Brain and Language, 5, 56–71) hypothesized that ample repetition of a small number of stimuli is required in order to obtain VHF differences in tachistoscopic tasks. Four experiments, with varied levels of repetition, were conducted to test this hypothesis. Three experiments utilized the general task of object-picture naming and one utilized a word-naming task. Naming latencies constituted the dependent measure. The results demonstrate that for the object-naming paradigm repetition is required for RVF superiority to emerge. Repetition was found to be unnecessary for RVF superiority in the word-naming paradigm, with repetition actually reducing RVF superiority. Experiment I suggested the possibility that RVF superiority developed for the second half of the trials as a function of practice or hemispheric activation, regardless of repetition level. Subsequent experiments, better designed to assess this possibility, clearly refuted it. It was concluded that the effect of repetition depends on the processing requirements of the task. We propose that, for tasks which can be processed efficiently by one hemisphere, the effect of repetition will be to reduce VHF asymmetries; but tasks requiring substantial processing by both hemispheres will show shifts to RVF superiority as a function of repetition.