On the impact of human operant research: Asymmetrical patterns of cross-citation between human and nonhuman research

Reactions to published accounts of research with human subjects, as well as research with nonhuman subjects, were assessed by examining citations in several samples of empirical articles in the Journal of the Experimental Analysis of Behavior. A stable, asymmetrical pattern emerged: Nonhuman research was cited in both human and nonhuman articles, but human research was cited primarily in human articles. Thus, human operant research appears to have had little influence on the nonhuman research which constitutes the bulk of the experimental analysis of behavior. Interpretation of this lack of impact depends on the functions one envisions for human research, several of which are discussed.     

Responsiveness to estrous chemostimuli in male rats (Rattus norvegicus) of different ages

Previous findings indicate that Norway rats (Rattus norvegicus) respond differentially to estrous chemostimuli in early infancy and that adult male sexual responsiveness to such chemostimuli depends on infantile experience with suckling odors (Fillion & Blass, in press). The development of behavioral responsiveness to estrous chemostimuli in male rats from late infancy to adulthood was examined in this study. Preweanling, adolescent, and adult males were observed for 20 min in the presence of an anesthetized estrous or an anesthetized diestrous female. This was, for adolescent and adult subjects, the first heterosexual encounter since weaning. Rats in each age-group responded differentially according to female state, but in distinct, age-related ways. Preweanling spent more time investigating the female's body if she was estrous. Adults expressed the same affinity but by more focused investigation directed perivaginally. Adolescents showed no female-directed bias but groomed themselves more if the female was estrous. These data identify developmental continuities and discontinuities in male rat behavior toward sexually receptive females.     

Infants’ sensitivity to the depth cue of shading

Five- and 7-month-old infants were tested for sensitivity to the depth cue of shading. Infants were presented with two displays: a surface in which a convexity and a concavity were molded and a photograph in which shading specified a convexity and a concavity. Each display was presented under both monocular and binocular viewing conditions. Reaching was observed as the dependent measure. Infants in both age groups reached preferentially for the actual convexity in both the monocular and binocular viewing conditions. In the monocular photograph condition, the 7-month-olds reached preferentially for the apparent convexity specified by shading, indicating that they perceived it to be an actual convexity. These infants showed no significant reaching preference in the binocular photograph condition. This finding rules out interpretations of the infants’ reaching not based on perceived depth. The results therefore suggest that the 7-month-olds perceived depth from shading. The 5-month-olds showed no significant reaching preferences when viewing the photograph; thus, they showed no evidence of depth perception from shading. These findings are consistent with the results of a number of studies that have investigated infants’ sensitivity to pictorial depth cues. Together, these studies suggest that the ability to perceive depth from pictorial cues may first develop between 5 and 7 months of age.     

Young children's attention to dyadic conversation as modified by sociometric status

Forty-eight American children, 12 popular and 12 rejected children from Grades 3 and 6, were paired with same-sex friends and nonfriends on an interactive task. Children were videotaped and their interactions judged for the amount and type of attention each child in the dyad gave to each other and the conversation. Main dependent measures included mutual engagements, acknowledgement of the partner, getting the attention of the partner, attention to the conversation, and social impact of the utterances. Both rejected and popular children attended to the conversation and the partner, but rejected children appeared to overattend in several ways. The interactions of rejected children and their matches involved more mutual engagements, conversational initiators, facilitators, terminators, and nonverbal attention-getting devices. Sex and developmental effects were also found.