Emotional state and the detection of change in facial expression of emotion

A new method is presented for examining effects of emotion in the detection of change in facial expression of emotion. The method was used in one experiment, reported here. Participants who were induced to feel happiness, sadness, or neutral emotion, saw computerized 100‐frame movies in which the first frame always showed a face expressing a specific emotion (e.g. happiness). The facial expression gradually became neutral over the course of the movie. Participants played the movie, changing the facial expression, and indicated the frame at which the initial expression was no longer present on the face. Emotion congruent expressions were perceived to persist longer than were emotion incongruent expressions. The findings are consistent with previous findings documenting enhanced perceptual processing of emotion congruent information. The value of the current technique, and the types of everyday situations that it might model are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Neonatal imitation in a mother–infant setting

Imitation of tongue protrusions and mouth openings was investigated in 18 newborn infants using a procedure differing in three ways from previous laboratory studies: the mother presented the target gestures, she was permitted to adjust to the infant's reactions, and the infant's baseline response rate was assessed during face-to-face interaction. This procedure was assumed to facilitate infant imitation. Compared with baseline responses in face-to-face interaction, both tongue protrusions and mouth openings were imitated in the two conditions. No imitation, however, was found when the responses in the two imitation conditions were compared. These results are less convincing than those found in strictly controlled laboratory experiments. A less restrictive procedure did not, therefore, promote imitation. The mixed results could be explained by too short an exposure to the target gesture. If repeated and insistent gesturing is a crucial condition, neonatal imitation might be understood to be the result of instruction and teaching, rather than a means of mutual communication. © 1998 John Wiley & Sons, Ltd.     

Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent

Adult male rats reared as pairmates from weaning were tested in a neutral arena with both members of another pair (one at a time). The unfamiliar pairs were found to engage in play fighting, although they were more likely to escalate the encounter into serious fighting than were pairs of familiar rats. Based on their within‐home pair behavior, each pairmate was designated as a dominant or a subordinate. When the test encounters between unfamiliar males were analyzed with regard to whether the pairings consisted of two dominants, two subordinates, or a mixed pair, the pattern of play fighting was found to be attenuated. Both dominants and subordinates were more likely to initiate playful encounters, to respond defensively during these encounters, and to do so using adult‐typical tactics of defense when paired with an unfamiliar rat that was dominant in its home cage. The mechanisms by which the home status of unfamiliar male rats can be identified by another male are discussed, particularly with regard to the role that play fighting may serve for this function. It is concluded that the data support the hypothesis that play fighting can be used by adult rats for social testing, which in this case seems to involve ascertaining the opponent's fighting capability. Aggr. Behav. 25:141–152, 1999. © 1999 Wiley‐Liss, Inc.     

Effect of body size on aggression in the ant,Cataglyphis niger (Hymenoptera; Formicidae)

In polymorphic ants, such as Cataglyphis niger, sterile individual workers from the same nest show some degree of variation in size and/or morphology. We studied whether worker size and size difference between opponents had an effect on aggression during conspecific encounters. Although the capacity to recognize nestmates was shared by all individuals, some patterns of agonistic behaviors were size related. Escape was mostly displayed by the small workers, and threat, associated with ritualized fights, by the large workers. As game theory predicted, ants of C. niger adjusted their level of aggression as a function of the size of the opponent. However, only large individuals used such assessment strategies, responding with escalation of aggression towards small workers and reduction of aggression towards large ones. On the contrary, small individuals behaved in the same manner whatever the opponent's size. Differences between both morphological castes were discussed with reference to the resource holding assessment models. Aggr. Behav. 25:369–379, 1999. © 1999 Wiley‐Liss, Inc.     

Identity processing style and cognitive attributional strategies: similarities and difference across different contexts

Identity processing style refers to the manner in which individuals approach or manage to avoid identity relevant problems and decisions. Two studies were designed to investigate the relationship between identity style and the specific cognitive and attributional strategies youth deploy in achievement and affiliative contexts. In Study 1, 198 American late adolescents filled in the revised Identity Style Inventory and a Strategy and Attribution Questionnaire. In Study 2, 109 Finnish late adolescents filled in the same measures. Study 1 revealed that diffuse/avoidant‐oriented American youth relied on maladaptive strategies in both contexts. Information‐oriented youth engaged in more strategic planning than did their normative and diffuse/avoidant counterparts. Study 2 indicated an identical pattern of associations among the identity processing styles and cognitive and attributional strategies for Finnish youth in achievement but not in interpersonal settings. The results are discussed in the context of a social–cognitive theory of identity development. Copyright © 1999 John Wiley & Sons, Ltd.     

Emotional interaction in a group of preterm infants at 3 and 6 months of corrected age

Twenty preterm infants (birthweight<1500 g) and 20 healthy fullterm infants were compared with respect to emotional interaction with their mothers in a face‐to‐face situation at 3 months of age and in a feeding situation at 6 months of age (ages corrected for preterm birth). The assessed outcome was analysed with respect to infant variables (group, gender, gestational age, birthweight and neonatal risk factors) and maternal variables (age, education and parity). The outcomes at 3 and 6 months of age were also compared with findings of Griffiths’ testing at 10 months of age. At 3 months of age, the findings reveal no significant difference between the two groups with respect to emotional interaction. Maternal variables are more important for this interaction than are infant variables. The mother's level of formal education has a significant impact in both groups. In the group of fullterm infants, significantly lower scores for interaction are obtained by first‐time mothers in comparison with multi‐parae mothers. At 6 months of age, the difference between fullterm and preterm infants is significant. The preterm infants and their mothers now relate to one another more poorly than is the case for the fullterm dyads. These findings suggest that the difficulties encountered by the preterm infant emerge with time. Emotional interaction at this age and the results of Griffiths’ testing 4 months later are significantly correlated. Copyright © 1999 John Wiley & Sons, Ltd.