Comparative cognitive development

This paper aims to compare cognitive development in humans and chimpanzees to illuminate the evolutionary origins of human cognition. Comparison of morphological data and life history strongly highlights the common features of all primate species, including humans. The human mother-infant relationship is characterized by the physical separation of mother and infant, and the stable supine posture of infants, that enables vocal exchange, face-to-face communication, and manual gestures. The cognitive development of chimpanzees was studied using the participation observation method. It revealed that humans and chimpanzees show similar development until 3 months of age. However, chimpanzees have a unique type of social learning that lacks the social reference observed in human children. Moreover, chimpanzees have unique immediate short-term memory capabilities. Taken together, this paper presents a plausible evolutionary scenario for the uniquely human characteristics of cognition.     

Tactics to obtain a hidden food item in chimpanzee pairs (Pan troglodytes)

Five dyads of chimpanzees were tested in a competitive situation, as a pilot study to examine chimpanzees' understanding of conspecifics' knowledge. A human experimenter baited one of five containers in an outdoor enclosure. Chimpanzee A (witness) could see where the food was hidden, while chimpanzee B (witness-of-witness) could not see the baited place but could observe the chimpanzee A watching the food being hidden. Then the two were released into the enclosure. This procedure was repeated for a certain number of days along with a control condition in which neither could see the baited location. The witness-of-witness developed tactics to forestall the witness in two pairs. The witness misled the witness-of-witness by taking a route to an empty container in several cases. These episodes might represent examples of deception. Tactics and counter-tactics thus developed through the interaction between the witness and the witness-of-witness, illustrating the high social intelligence of chimpanzees. An examination of the changes in tactics suggests a possibility that the witness-of-witness understands the witness's knowledge of the location of hidden food. Accepted after revision: 22 May 2001 Electronic Publication     

Causal relationship between Internet use and social capital in Japan

Based on longitudinal data collected from a random sample panel survey, the present study found that different types of Internet usage are differentially related to social networks. The more social ties people have, the more likely they are to use personal computer (PC) email, and the use of PC email increases social ties. The results also show that the more supportive ties people have, the more they tend to use mobile phone email; however, it does not prove the use of mobile phone email increases supportive ties. However, participation in an online community is not related social networks. These findings suggest that PC email may increase the size of personal social networks, whereas mobile phone email is useful in maintaining existing strong ties which provide social support.     

Auditory–visual intermodal matching based on individual recognition in a chimpanzee (Pan troglodytes)

The ability to recognize familiar individuals with different sensory modalities plays an important role in animals living in complex physical and social environments. Individual recognition of familiar individuals was studied in a female chimpanzee named Pan. In previous studies, Pan learned an auditory–visual intermodal matching task (AVIM) consisting of matching vocal samples with the facial pictures of corresponding vocalizers (humans and chimpanzees). The goal of this study was to test whether Pan was able to generalize her AVIM ability to new sets of voice and face stimuli, including those of three infant chimpanzees. Experiment 1 showed that Pan performed intermodal individual recognition of familiar adult chimpanzees and humans very well. However, individual recognition of infant chimpanzees was poorer relative to recognition of adults. A transfer test with new auditory samples (Experiment 2) confirmed the difficulty in recognizing infants. A remaining question was what kind of cues were crucial for the intermodal matching. We tested the effect of visual cues (Experiment 3) by introducing new photographs representing the same chimpanzees in different visual perspectives. Results showed that only the back view was difficult to recognize, suggesting that facial cues can be critical. We also tested the effect of auditory cues (Experiment 4) by shortening the length of auditory stimuli, and results showed that 200 ms vocal segments were the limit for correct recognition. Together, these data demonstrate that auditory–visual intermodal recognition in chimpanzees might be constrained by the degree of exposure to different modalities and limited to specific visual cues and thresholds of auditory cues.     

Acquisition and memory of sequence order in young and adult chimpanzees (Pan troglodytes)

There is no research about age difference in the process of sequential learning in non-human primates. Is there any difference between young and adults in sequential learning process? Six chimpanzees (Pan troglodytes), 3 young and 3 adults, learned the Arabic numeral sequence 1 to 9 by touching the numerals on a touch-screen monitor in ascending order. Initially, the sequence always started with the numeral 1, i.e. ‘start-fixed task’. Training began with the sequence 1–2, 1–2–3, and continued sequentially up to 1–2–3–4–5–6–7–8–9. Later, the subjects were introduced to sequences that started with a random numeral, but always ended with 9, i.e. ‘end-fixed task’. Performance in the end-fixed task was worse relative to the familiar start-fixed task. After training with various sequences of adjacent numerals, the subjects were given a transfer test for the non-adjacent numerals. The results suggested that all chimpanzees indeed mastered sequential ordering, and although there was no fundamental difference in the acquisition process between the two age groups, there was a significant age difference in memory capacity. Based on their knowledge of sequential ordering, the subjects were then asked to perform a masking task in which once a subject touched the lowest numeral, the other numeral(s) turned to white squares. Performance of the masking task by young chimpanzees was better than that of adults in accuracy and degree of difficulty (number of numerals). Taken together, these data clearly demonstrate a similarity among subjects in the way chimpanzees acquire knowledge of sequential order regardless of age differences in sequential learning. Moreover, they reveal that once knowledge of sequential order is established, it can be a good index used to evaluate memory capacity in young and adult chimpanzees.

     

The Impact of Crime on Social Ties and Civic Participation

The present study examined associations of neighbourhood crime with residents' social ties and civic participation using multilevel models. We hypothesized that crime is indirectly associated with residents' low civic participation by negatively relating to their acquaintanceship ties because of fear of neighbours. By contrast, we predicted that crime is indirectly related to frequent civic participation by positively associating with more intimate friendship ties as a response to combat external threats. Additionally, we hypothesized that high crime rates in the neighbourhood increases the importance of generalized trust towards others. Therefore, we examined the interaction effects of neighbourhood crime and trust on social ties and participation. The study is based on a postal questionnaire mailed to residents aged between 20 and 69 years, residing in Musashino City and Kiyose City, in Tokyo. Rates of larceny reported by the Tokyo Metropolitan Police Department were used as indices of neighbourhood crime. As hypothesized, our results showed that crime is positively associated with friendship ties and is negatively related to acquaintanceship ties. Through these opposing relationships, crime showed both positive and negative associations with civic participation. Moreover, we found that generalized trust buffered the adverse relationships between crime, broader social ties and participation. Copyright © 2015 John Wiley & Sons, Ltd.     

Bridging Social Capital in Online Communities: Heterogeneity and Social Tolerance of Online Game Players in Japan

This article examines the democratic potential of online communities by investigating the influence of network heterogeneity on social tolerance in an online gaming environment. Online game communities are potential sources of bridging social capital because they tend to be relatively heterogeneous. Causal analyses are conducted using structural equation modeling with survey data collected in a three‐wave panel of online game players in Japan. Results show that the heterogeneous composition of online community causally enhances social tolerance toward community members within the online gaming setting. Furthermore, results show that enhanced social tolerance toward online community members is generalized to offline settings. This causal process suggests that online communities provide access to bridging social capital by gathering heterogeneous populations around shared contexts.