Senders" viewed 25 emotionally loaded color slides. Their facial expressions were observed via a hidden television camera by "observers" who made judgments about the nature of each slide and the sender's reaction to it. A total of 64 undergraduates were arranged in eight pairings each of females sending to male observers, females sending to females, males sending to males, and males sending to females. Statistically significant communication was demonstrated, with females being more accurate senders than males. More accurate senders tended to show a smaller skin conductance and heart rale response to the slides and a more "personal" verbal report of their emotional reaction to the slides. Several personality measures were related to communication accuracy and physiological responding. * Internalizer versus externalizer, * p < .10. ** p < .05. *** p < .01.

This typology of biological affects is based on developmental-interactionist theory of motivation, emotion, and cognition. Affects--subjectively experienced feelings and desires--involve interoceptive perceptual systems based on primordial molecules that characterize neurochemicals. Biological affects involve primary motivational-emotional systems (primes) associated with hierarchically organized neurochemical systems in the brain, including subcortical (reptilian) and paleocortical (limbic) brain structures. Affects fulfill individualistic (selfish) functions (arousal, approach-avoidance, agonistic) and prosocial (cooperative) functions. Selfish and cooperative functions are associated respectively with the right and left hemispheres. Biological affects constitute the physiological bases for higher level affects: social affects (e.g., pride, guilt, shame, pity, jealousy), cognitive affects (e.g., curiosity, surprise), and moral affects.

The facial feedback hypothesis, that skeletal muscle feedback from facial expressions plays a causal role in regulating emotional experience and behavior, is an important part of several comtemporary theories of emotion. A review of relevant research indicates that studies reporting support for this hypothesis have, without exception, used within-subjects designs and that therefore only a restricted version of the hypothesis has been tested. Also, the results of some of these studies must be questioned due to demand characteristics and other problems. It is suggested that visceral feedback may make a more direct contribution to emotional processes than facial feedback does and that the "readout" functions of facial expressions are more important than any feedback functions. The author thanks Reuben Baron and Robert E. Miller for their comments and suggestions on this article. Requests for reprints should be sent to Ross Buck,

The communication of affect through spontaneous facial expressions was studied with 10 pairs of female undergraduates and 9 pairs of males. "Sender" subjects watched 25 slides designed to elicit affect while "observers" watched the sender's face over television and made judgments about the nature and intensity of the affect. Skin conductance and heart rate were recorded from both sender and observer. Results revealed significant communication of affect, particularly among the female pairs. Relationships between the communication process, personality measures, and physiological responding were explored, and a negative relationship was found between the sender's skin conductance responding and communication accuracy.

Motivation and emotion are viewed as different aspects of a single process in which emotion involves the "readout" of motivational potential inherent in hierarchically organized primary motivational/emotional systems (primes). The most basic readout, Emotion 7, involves adaptive-homeostatic functions. In species where communication about the state of certain primes became important, Emotion II, involving their outward expression, evolved. With cognition, a third type of readout evolved, Emotion III, involving the direct experience of certain primes. A model of the interaction between primes and cognition is presented, and the unique role of language in human motivation-emotion is discussed. I would like to thank a number of colleagues including Reuben Baron, Paul Ekman, Phoebe Ellsworth, several anonymous reviewers, and particularly, Carroll Izard and the Editor for their valuable comments and suggestions on this article.