How monkeys see the eyes: cotton-top tamarins’ reaction to changes in visual attention and action

Among social species, the capacity to detect where another individual is looking is adaptive because gaze direction often predicts what an individual is attending to, and thus what its future actions are likely to be. We used an expectancy violation procedure to determine whether cotton-top tamarins (Saguinus oedipus oedipus) use the direction of another individual’s gaze to predict future actions. Subjects were familiarized with a sequence in which a human actor turned her attention toward one of two objects sitting on a table and then reached for that object. Following familiarization, subjects saw two test events. In one test event, the actor gazed at the new object and then reached for that object. From a human perspective, this event is considered consistent with the causal relationship between visual attention and subsequent action, that is, grabbing the object attended to. In the second test event, the actor gazed at the old object, but reached for the new object. This event is considered a violation of expectation. When the actor oriented with both her head-and-eyes, subjects looked significantly longer at the second test event in which the actor reached for the object to which she had not previously oriented. However, there was no difference in looking time between test events when the actor used only her eyes to orient. These findings suggest that tamarins are able to use some combination of head orientation and gaze direction, but not gaze direction alone, to predict the actions of a human agent. Received: 17 February 1999 / Accepted after revision: 9 May 1999     

The Effects of Direct Questions on Preschool Children's Responses to Indirect Requests

Indirect instructional approaches, such as responsive interaction, are common in inclusive early childhood settings. Unfortunately, young children with disabilities do not always have the skills to take advantage of these learning opportunities. Teaching children with disabilities to be more responsive to developmentally appropriate indirect instructional strategies may help them take advantage of and benefit from available learning opportunities in inclusive settings. The purpose of this research was to examine the extent to which presenting a series of direct questions increased children's attempts to respond and correct responses to indirect requests. Increased attempts to respond and correct responses to indirect requests were evident for all participants with whom the intervention was implemented. Three of the participants continued to attempt to respond and responded correctly to indirect requests when intervention procedures were removed. The contributions of these findings to literature on language instruction with young children, implications of the findings for practitioners, methodological limitations, and suggestions for future research are discussed.     

INCREASING VERBAL INTERACTION AMONG ELDERLY SOCIALLY ISOLATED MENTALLY RETARDED ADULTS: A GROUP LANGUAGE TRAINING PROCEDURE

The present study examined the effectiveness of a group language training procedure for directly increasing and generalizing the rate of verbal interaction among four elderly, socially isolated, moderately mentally retarded men. A withdrawal of treatment design was used to examine the effect of the procedure that used verbal prompts, behavioral rehearsal, and contingent social praise. Changes in behavior were examined in two generalization settings, one similiar to the training environment (Generalization I) and the other arranged as part of the subjects' daily routine (Generalization II). Baseline data indicated no verbal interaction among the subjects. During treatment the training procedure increased the rate of subjects' verbal interactions not only in the training situation, but also in the two generalization settings. An analysis of the data obtained during the Generalization II situation indicated that subjects' verbal interaction increased not only among themselves, but with nonsubject peers present in this setting. Follow-up data showed that increases in rates of verbal interaction were maintained four months after the cessation of training. The implications of the results for program generalization and work with the language deficient individual is discussed.     

Psychological Variables as Predictors of Perceived Ethnic Discrimination Among Minority and Immigrant Adolescents1

The occurrence of discrimination in the real world is difficult to determine objectively, as it is defined in part by intentions. The perception of discrimination may therefore be influenced by one's interpretation of the intentions of others. In order to examine psychological characteristics that influence the perception of ethnic discrimination, 164 Armenian, Mexican American, and Vietnamese adolescents completed measures of perceived discrimination (PD), self-esteem, mastery, depression/anxiety, intergroup competence, and ethnic identity, as well as demographic variables. A path analysis showed that higher depression/anxiety scores and lower intergroup competence predicted more PD; depression/anxiety and intergroup competence were in turn predicted by self-esteem and mastery, respectively. Birthplace and socioeconomic status had an indirect effect on PD, via intergroup competence. The results suggest the importance of psychological variables in the perception of discrimination.     

A non‐human primate’s understanding of solidity: dissociations between seeing and acting

Studies often reveal a dissociation between what infants know as revealed by action and what they know as revealed by perception. We explored whether non‐human primates exhibit a similar dissociation, focusing on what rhesus macaques know about solidity. In a series of search experiments, Hauser (2001) found that rhesus do not possess a complete understanding of solidity, searching below a solid shelf for an invisibly displaced object. In the present experiments, we explored how rhesus would perform in expectancy violation versions of the same tasks. Subjects looked longer when an apple appeared to fall through a solid shelf and when it appeared to roll through a solid barrier. These results suggest that macaques have some understanding of solidity when tested using looking paradigms even though they do not appear to use this knowledge when searching for food. We speculate that this dissociation is similar to that demonstrated in human development.     

Oceans of stimuli: an individual-based model to assess the role of olfactory cues and local enhancement in seabirds’ foraging behaviour

Animal Cognition - Oceans are extremely dynamic environments, which poses challenges for top-predators such as seabirds to find food resources. Yet, seabirds evolved sensorial abilities (olfactory...     

The Critical Point to Step into a Hole is Similar in Young and Older Adults

Abstract

The avoidance of a hole in the pathway while walking has been systematically investigated; however, depending on the dimensions of the hole, the option to avoid it is infeasible, and it is necessary to use the so-called accommodation strategy to step into the hole. We investigated the critical point between the avoidance and accommodation strategies when dealing with a hole in the ground during locomotion of young and older adults. Young and older adults performed two tasks: verbal estimation and walking. We used holes of different lengths and constant depth (12?cm). In the verbal estimation task, participants stood and looked at each hole and verbally respond if they would step into or avoid it. In the walking task, they walked and chose to either step or avoid the hole. Both age groups preferred to step into the hole when it was larger than 1.3 times their foot length in both tasks. The perception of affordances of young and older adults to step into a hole was similar, and it was unaffected by the investigated tasks. Thus, our participants preferred to have a safety margin that was large enough to guarantee that the whole foot would accommodate within the hole.     

Race Bias Tracks Conception Risk Across the Menstrual Cycle

ABSTRACT— Although a considerable body of research explores alterations in women's mating-relevant preferences across the menstrual cycle, investigators have yet to examine the potential for the menstrual cycle to influence intergroup attitudes. We examined the effects of changes in conception risk across the menstrual cycle on intergroup bias and found that increased conception risk was positively associated with several measures of race bias. This association was particularly strong when perceived vulnerability to sexual coercion was high. Our findings highlight the potential for hypotheses informed by an evolutionary perspective to generate new knowledge about current social problems—an avenue that may lead to new predictions in the study of intergroup relations.     

Adolescents in Transition to Adulthood: Parental Support, Relationship Satisfaction, and Post-transition Adjustment

The transition from high school is a pivotal period for intergenerational relations, as the asymmetry characterizing pre-transition relations with parents is reconfigured. Changes in adolescent–parent relations across this transition have potentially important implications for post-transition adjustment. A prospective study was conducted with an ethnically diverse sample that included adolescents who were not college-bound. Maternal, but not paternal, relations improved across the transition from high school to adult life. Changes in support from both mothers and fathers were associated with changes in relationship satisfaction and changes in satisfaction predicted post-transition adjustment. The results verify the importance of parental support to the quality of relational bonds between young adults and their parents. They also affirm the significance of these bonds for post-transition adjustment.