Facial expression is a mode of close‐proximity non‐vocal communication used by primates and is produced by mimetic/facial musculature. Arguably, primates make the most‐intricate facial displays and have some of the most‐complex facial musculature of all mammals. Most of the earlier ideas of primate mimetic musculature, involving its function in facial displays and its evolution, were essentially linear “scala natural” models of increasing complexity. More‐recent work has challenged these ideas, suggesting that ecological factors and social systems have played a much larger (...) role in explaining the diversity of structures than previously believed. The present review synthesizes the evidence from gross muscular, microanatomical, behavioral and neurobiological studies in order to provide a preliminary analysis of the factors responsible for the evolution of primate facial musculature with comparisons to general mammals. In addition, the unique structure, function and evolution of human mimetic musculature are discussed, along with the potential influential roles of human speech and eye gaze. BioEssays 30:212–225, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

Provides a comprehensive report on the mother-child bond and the emotional effects of and behavioral response to maternal deprivation.

In this article I evaluate recent attempts to illuminate the human infant cry from an evolutionary perspective. Infants are born into an uncertain parenting environment, which can range from indulgent care of offspring to infanticide. Infant cries are in large part adaptations that maintain proximity to and elicit care from caregivers. Although there is not strong evidence for acoustically distinct cry types, infant cries may function as a graded signal. During pain-induced autonomic nervous system arousal, for example, neural input to (...) the vocal cords increases cry pitch. Caregivers may use this acoustic information, together with other cues, to guide caregiving behavior. Serious pathology, on the other hand, results in chronically and severely abnormal cry acoustics. Such abnormal crying may be a proximate cause of adaptive infant maltreatment, in circumstances in which parents cut their losses and reduce or withdraw investment from infants with low survival chances. An increase in the amount of crying during the first few months of life is a human universal, and excessive crying, or colic, represents the upper end of this normal increase. Potential signal functions of excessive crying include manipulation of parents to acquire additional resources, honest signaling of need, and honest signaling of vigor. Current evidence does not strongly support any one of these hypotheses, but the evidence is most consistent with the hypothesis that excessive early infant crying is a signal of vigor that evolved to reduce the risk of a reduction or withdrawal of parental care. Key Words: colic; crying; early infant crying; honest signaling; infanticide; parental care; parent-offspring conflict; separation call; vocalization. (shrink)

Functional theories posit that emotions are elicited by particular goal-related situations that represented adaptive problems and that emotions are evolved features of coordinated responses to those situations. Yet little theory or research has addressed the evolutionary aspects of these theories. We apply five criteria that can be used to judge whether features are adaptations. There is evidence that sadness, anger, and anxiety relate to unique changes in physiology, cognition, and behavior, those changes are correlated, situations that give rise to emotions (...) are consistent, and emotions are complex. To date, there is little experimental evidence regarding whether discrete emotions resolve adaptive problems and do so relatively efficiently. Evidence supporting all criteria is required to claim that discrete emotions are evolved features. (shrink)

What is ethics? Where do moral standards come from? Are they based on emotions, reason, or some innate sense of right and wrong? For many scientists, the key lies entirely in biology---especially in Darwinian theories of evolution and self-preservation. But if evolution is a struggle for survival, why are we still capable of altruism? In his classic study The Expanding Circle, Peter Singer argues that altruism began as a genetically based drive to protect one's kin and community members but has (...) developed into a consciously chosen ethic with an expanding circle of moral concern. Drawing on philosophy and evolutionary psychology, he demonstrates that human ethics cannot be explained by biology alone. Rather, it is our capacity for reasoning that makes moral progress possible. In a new afterword, Singer takes stock of his argument in light or recent research on the evolution of morality.--Publisher's description. (shrink)

With the discovery of conditioned reflexes by I. P. Pavlov, the possibilities for experimenting, following the example set by the classical, exact sciences, were made available to the behavioral sciences. Many psychologists hoped that the component parts of behavior had also been found from which the entire, multifaceted cosmos of behavior could then be constructed. An experimentally oriented psychology subsequently developed including the influential school of behaviorism. This first text on human ethology presents itself as a unified work, even though (...) not every area could be treated with equal depth. For example, a branch of ethology has developed in the past decade which places particular emphasis on ecology and population genetics. This field, known as sociobiology, has enriched discussion beyond the boundaries of behavioral biology through its stimulating, and often provocative, theses. After vigorous debates between behaviorists, anthropologists, and sociologists, we have entered a period of exchange of thoughts and a mutual approach, which in many instances has led to cooperative projects of researchers from different disciplines. This work offers a biological point of view for discussion and includes data from the author's cross-cultural work and research from the staff of his institute. It confirms, above all else, the astonishing unity of mankind and paints a basically positive picture of how we are moved by the same passions, jealousies, friendliness, and active curiosity. The need to understand ourselves has never been as great as it is today. An ideologically torn humanity struggles for its survival. Our species, does not know how it should compensate its workers, and it experiments with various economic systems, constitutions, and forms of government. It struggles for freedom and stumbles into newer conflicts. Population growth is apparently completely out of hand, and at the same time many resources are being depleted. We must consider our existence rationally in order to understand it, but certainly not with cold, calculating reason but with the warm feeling of a heart concerned for the welfare of later generations. (shrink)

In this paper, we argue that, barring a few important exceptions, the phenomenon we refer to using the expression “being moved” is a distinct type of emotion. In this paper’s first section, we motivate this hypothesis by reflecting on our linguistic use of this expression. In section two, pursuing a methodology that is both conceptual and empirical, we try to show that the phenomenon satisfies the five most commonly used criteria in philosophy and psychology for thinking that some affective episode (...) is a distinct emotion. Indeed, being moved, we claim, is the experience of a positive core value (particular object) perceived by the moved subject as standing out (formal object) in the circumstances triggering the emotion. Drawing on numerous examples, we describe the distinctively rich phenomenology characteristic of the experience as well as the far-reaching action-tendencies and functions associated with it. Having thus shown that the candidate emotion seem to satisfy the five criteria, we go on, in section three, to compare it with sadness and joy, arguing that it should not be confused with either. Finally, in section four, we illustrate the explanatory power of our account of “being moved” by showing how it can shed light on, and maybe even justify, the widespread distrust we feel towards the exhibition of ‘sentimentality’. On the whole and if we are right, we have uncovered an emotion which, though never or rarely talked about, is of great interest and no small importance. (shrink)

Until now, adult crying has received relatively little interest from investigators, whereas in the popular media there are many strong claims about crying (e.g., crying brings relief) of which the scientific basis is not clear. In this review, we provide an overview of the current state of the scientific literature with respect to crying. We identify gaps in knowledge and propose questions for future research. The following topics receive special attention: Ontogenetic development, antecedents, individual and gender differences, and the intra- (...) and interindividual effects of crying. We conclude that the study of crying may help us obtain better insight into human nature, that is, not only our emotional, but also social, and moral functioning. (shrink)