Louis G. Tassinary

Inferring psychological significance from physiological signals.

A century has passed since the publication of William Jamess Principles of Psychology, yet most of the questions James raised about the relation between physiological events and molar psychological or behavioral processes, such as emotion, remain unanswered. The sluggish progress in capitalizing on physiological signals to address general psychological questions is due in part to shortcomings in the quantification of physiological signals in humans and, perhaps more important, to the way in which investigators have been thinking about the relation between physiological signals and psychological operations. In this article, we illustrate these points, and we provide a conceptual framework to foster research and analysis of psychological phenomena based on physiological signals. Psychological operations and physiological responses are defined in terms of configural and temporal properties, and psychophysiological relations are conceptualized in terms of their specificity (e.g., one-to-one versus many-to-one) and their generality (e.g., situation or person specific versus cross-situational and pancultural). This model yields four classes of psychophysiological relations: (a) outcomes, (b) concomitants, (c) markers, and (d) invariants. Finally, the model specifies how to determine whether a psychophysiological relation is an outcome, concomitant, marker, or invariant, and it describes important limitations in inferences of psychological significance based on physiological signals when dealing with each.

Personality, emotional experience, and efforts to control emotions

Three converging, multimethod studies examined personality and emotional processes. Study 1 (N = 321) examined links among sex, personality, and expectations for emotional events. In Study 2, participants (N = 468) described contents of emotionally evocative slides to a partner (either a friend or a stranger). Participants reported their emotional experience, efforts to control emotion, and the anticipated reactions of their partners. Structural modeling of self-report data and analyses of observational data indicated that Agreeableness and sex were significant predictors of emotional experience and of efforts to control emotion. Study 3 (N = 68) replicated and extended the two previous studies using psychophysiological methods to examine responses to positively and negatively charged emotional materials. Outcomes are discussed in terms of processes underlying the five-factor structural dimension of Agreeableness and links to emotional self-regulation.

Swagger, Sway, and Sexuality: Judging Sexual Orientation From Body Motion and Morphology

People can accurately judge the sexual orientation of others, but the cues they use have remained elusive. In 3 studies, the authors examined how body shape and motion affect perceived sexual orientation. In 2 studies, participants judged the sexual orientation of computer-generated animations in which body shape and motion were manipulated. Gender-typical combinations (e.g., tubular body moving with shoulder swagger or hourglass body moving with hip sway) were perceived generally to be heterosexual; gender-atypical combinations were perceived generally to be homosexual. These effects were stronger for male targets. Body shape affected perceived sexual orientation of women, but motion affected perceived sexual orientation of both men and women. Study 3 replicated and extended these findings. Participants judged dynamic outlines of real people (men and women, both gay and straight) in which body shape and motion were measured. Again, gender-atypical body motion affected perceived sexual orientation and, importantly, affected accuracy as well.

Specific forms of facial EMG response index emotions during an interview: From Darwin to the continuous flow hypothesis of affect-laden information processing.

Previous research has demonstrated that mild negative emotional imagery and unpleasant sensory stimuli lead to greater electromyographic activity over the brow muscle region than mild positive imagery and stimuli, even in the absence of significant changes in visceral and general facial EMG activity. Previous research has not addressed whether electromyographic responses over the brow region are a sensitive and specific index of emotions, however, since a multiplicity of events lead to changes in brow activity. In this research, facial electromyographic and audiovisual recordings were obtained while individuals were interviewed about themselves. Afterwards, individuals were asked to describe what they had been thinking of during specific segments of the interview marked by distinctive electromyographic responses over the brow region in the context of ongoing but stable levels of activity elsewhere in the face. The results are interpreted in terms of a continuous flow hypothesis of affect-laden information processing.

A Critical Test of the Waist-to-Hip-Ratio Hypothesis of Female Physical Attractiveness

Recent research has led to increasingly sophisticated conjectures as to the roles that genetic heritage, prior experience, and environmental context play in the production and maintenance of complex behaviors. The field of evolutionary psychology was born of such conjectures (Stanley, 1895) and now serves as a niche for a growing number of researchers (Buss, 1995; Kenrick, 1994). One of the more provocative lines of experimental research to emerge from this alembic derives from the linkage of evolutionary theories of human mate selection with definitions of physical attractiveness based on somatic characteristics that simultaneously signal attractiveness and predict reproductive potential (Buss, 1989). The waist-to-hip ratio (WHR) has been purportedly demonstrated to be a robust example of just such an invariant perceptual cue (e.g., Henss, 1995; Singh, 1993a). Here, we report that judgments of attractiveness and fecundity can be either unrelated or related, positively or negatively, to the WHR depending on waist size, hip size, and weight, and are thus inconsistent with the evolutionary argument that human physical attractiveness is fundamentally a sign of mate value.

Unobservable Facial Actions and Emotion

Surface electromyographic recordings in humans were first made less than 70 years ago, and the electromyographic study of covert facial actions during affect and emotion has less than a 20-year history. Despite the relative youth of facial electromyography, its use in combination with autonomic measures and comprehensive overt facial action coding systems has provided a sensitive and effective armamentarium for investigating emotion and affect-laden information processing. Research over the past decade has demonstrated that facial electromyographic activity varies as a function of the intensity, valence, and sociality of emotional stimuli and shows that facial electromyographic activity is slightly different in deliberately manipulated and spontaneous expressions of emotion. The multiply determined nature of facial actions and expressions, however, has limited the inferences that can be made about the psychological significance of facial electromyographic responses. These limitations have begun to recede in recent years as a result of advances in the psychometric properties of facial electromyographic measurements, the quantification of electromyographic waveforms and patterns, the conjoint measurement of facial electromyographic and electro-cortical activity, the conceptualization of psychophysiological relations, and the formalization of psychophysiological inference.

Microexpressive Facial Actions as a Function of Affective Stimuli: Replication and Extension

The effects of communicative intent and stimulus affectivity on facial electromyogrqphic (EMG) activity were investigated. Subjects viewed slides of pleasant, neutral, or unpleasant social or nature scenes under no instruction, inhibit-expression instructions, and amplify-expression instructions. Results revealed that facial EMG activity was highest in the amplify and lowest in the inhibit condition; EMG activity over the corrugator supercilii region varied as a function of the affective valence of the stimuli regardless of instructional condition; and facial EMG activity did not differ when subjects were exposed to slides of nature versus social scenes that were matched for rated pleasantness. These results suggest that facial efference can be altered by both affective and communicative processes even when it is too subtle to produce a socially perceptible facial expression.

Perceiving Sex Directly and Indirectly Meaning in Motion and Morphology

We employed a novel technique to explore how the bodys motion and morphology affect judgments of sex and gender. Stimuli depicted animated human walkers that varied in motion (gait patterns varying shoulder swagger and hip sway) and in morphology (waist-to-hip ratio). The potency of morphology in categorical sex judgments was confirmed. Visual scanning of the walkers was concentrated in the waist and hip region of the body (Study 1a). This targeted scanning was attenuated, however, when the sex of the target had been prespecified (Study 1b). Body motion permitted categorical judgments of sex, but these judgments were mediated by perceived gender (Study 2). These studies provide converging evidence for the primacy of the bodys shape in categorical judgments of sex.

Anger and Stress The Role of Landscape Posters in an Office Setting

Anger and stress management have become important issues in the modern workplace. One out of four American workers report themselves to be chronically angry, which has been linked to negative outcomes such as retaliatory behavior, revenge, interpersonal aggression, poor work performance, absenteeism, and increased turnover. We hypothesized that people who work in office environments decorated with aesthetically engaging art posters would experience less stress and anger in response to task-related frustration. Two hundred and ten college students were randomly assigned to different office conditions where abstract and nature paintings were hung on the walls. Participants performed four mild anger-provoking computer tasks and then reported their levels of state anger and stress. Results indicate that different office conditions had a significant influence on state anger and stress for males but not for females. Males experienced less state anger and stress when art posters were present. Through mediation analysis, we found that increased proportions of nature paintings decreased state anger because of decreased levels of stress.

Compatibility of basic social perceptions determines perceived attractiveness

The human bodys shape and motion afford social judgments. The bodys shape, specifically the waist-to-hip ratio, has been related to perceived attractiveness. Early reports interpreted this effect to be evidence for adaptation, a theory known generally as the waist-to-hip ratio hypothesis. Many of the predictions derived from this perspective have been empirically disconfirmed, leaving the issue of natural selection unresolved. Knowing the cognitive mechanisms undergirding the relationship between judgments of attractiveness and body cues is essential to understanding its evolution. Here we show that perceived attractiveness covaries with body shape and motion because they cospecify social percepts that are either compatible or incompatible. The bodys shape and motion provoke basic social perceptions, biological sex and gender (i.e., masculinity/femininity), respectively. The compatibility of these basic percepts predicts perceived attractiveness. We report evidence for the importance of cue compatibility in five studies that used diverse stimuli (animations, static line-drawings, and dynamic line-drawings). Our results demonstrate how a proximal cognitive mechanism, itself likely the product of selection pressures, helps to reconcile previous contradictory findings.