Influence of Pair-housing on Sleep Parameters Evaluated with Actigraphy in Female Rhesus Monkeys

Rhesus monkeys are naturally social animals, and behavioral management strategies have focused on promoting pairhousingin laboratory settings as an alternative to individual or group housing. In humans, co-sleeping can have a major impact on bed partners’ sleep, raising the possibility that pair-housing also may influence sleep parameters in monkeys. In the present study, we investigated if pair-housing would impact home-cage partner’s sleep in female rhesus monkeys, and if nighttime separation using socialization panels would alter this pattern. Sleep parameters of 10 experimentally naïve adult female rhesus monkeys (5 pairs) were evaluated for 7 consecutive days using actigraphy monitors attached to primate collars. Paired animals then were separated by socialization panels during the night, and sleep-associated measures were evaluated for 7 consecutive days. The data showed that sleep efficiency was significantly lower when monkeys were pairhoused as compared with when they were separated. On the nights when subjects were pair-housed, a positive correlation was detected for sleep measures (both sleep latency and efficiency) of both members of a pair (R2’s = 0.16–0.5), suggesting that pair-housing influences sleep quality. On nights when subjects were separated, no correlations were observed for sleep measures between members of the pairs (R2’s = 0.004–0.01), suggesting that when separated, the home-cage partner’s sleep no longer influenced the partner’s sleep. Our results indicate that pair-housing has a strong impact on the home-cage partner’s sleep, and that this pattern can be prevented by nighttime separation using socialization panels. Studies evaluating sleep in pair-housed monkeys should consider the effects that the partner’s sleep may have on the subject’s sleep. Sleep is a biologic phenomenon and experimental outcome that affects physical and behavioral health and altered sleep due to pair-housing may affect a range of research outcomes.

Yorùbá Ethics of Interpersonal Relations in Ọbasá’s Poetry

In the context of Yorùba interrelation, every human being is involved with ́ a clearly defined tradition laced with mutual benefits. The custom of human interpersonal relationship and the challenges thereof are critical issues in modern Yorùbá society. The themes of Yorùbá ethics as related to interpersonal relation are prominent in Obasa ̣’s poetry. In this essay, we identify and ́ analyze the ethical themes in Obasa ̣’s poetry and compare the poet’s engagement with the Yorùbá philosophy with a view to establish their relevance to the contemporary Yorùbá society. Wolfgang Iser’s (1996) principle on hermeneutics that “(texts) impacts information to the reader vis-a-vis the reader’s experience” is our model for the analysis of this paper (63). The ethical issues in Obasa’s poetry are anchored ́ to three sociocultural Yoruba concepts: communalism, cultural ideology on salutation, and conflict resolution. Tis paper affirms the poet’s rational reflection on the Yorùbá cultural ideology and pragmatic approach to ethical issues. As I argue in the essay, the poet’s perspectives affirm the basis of Yorùba ethical concepts on communalism and how it portrays human beings ́ as social “animals.”

Culturing Belief

What kind of being are we? This of course is one of the oldest questions in philosophy. In earlier eras, answers were often non-naturalistic (we are animals with souls, for instance). Today, one of the oldest answers is also one of the most popular: with Aristotle, we often think we are distinguished from other animals by our rationality. This chapter suggests that another answer is at least as defensible: we are epistemically social animals. In making the case for this answer, it provides some of the background for the account of belief formation developed in the book. It highlights evidence from cultural evolution for our epistemic dependence on one another. Cultural evolution shows how human flourishing is due to cultural knowledge that escapes the grasp of individuals and that is the product of evolutionary processes. The chapter then turns to our central paradigm of a successful epistemic enterprise: modern science. It argues that science, too, owes its success to the way in which cognition is distributed across agents, groups, and even artifacts.

‘Dazed and Confused!’ Context and Social Disconnect in the Time of Pandemic

Humans are social animals. Our sense of identity and ‘self’ is defined in part by the roles we perform in the social groups to which we belong. This article discusses some of the variables that contribute to our sense of self, including language, place of origin, education and shared social norms. It also outlines some of the general mechanisms that underpin our various social networks. In its final part, this article reviews the impact of social isolation, such as that happened during the COVID pandemic, on these social mechanisms and the resulted disruption of psychological wellbeing in individuals diagnosed with dementia.

Formant-Based Recognition of Words and Other Naturalistic Sounds in Rhesus Monkeys

In social animals, identifying sounds is critical for communication. In humans, the acoustic parameters involved in speech recognition, such as the formant frequencies derived from the resonance of the supralaryngeal vocal tract, have been well documented. However, how formants contribute to recognizing learned sounds in non-human primates remains unclear. To determine this, we trained two rhesus monkeys to discriminate target and non-target sounds presented in sequences of 1–3 sounds. After training, we performed three experiments: (1) We tested the monkeys’ accuracy and reaction times during the discrimination of various acoustic categories; (2) their ability to discriminate morphing sounds; and (3) their ability to identify sounds consisting of formant 1 (F1), formant 2 (F2), or F1 and F2 (F1F2) pass filters. Our results indicate that macaques can learn diverse sounds and discriminate from morphs and formants F1 and F2, suggesting that information from few acoustic parameters suffice for recognizing complex sounds. We anticipate that future neurophysiological experiments in this paradigm may help elucidate how formants contribute to the recognition of sounds.

Submission signals in animal groups

Aggression is costly, and animals have evolved tactics to mitigate these costs. Submission signals are an underappreciated example of such adaptations. Here we review submissive behaviour, with an emphasis on non-primates. We highlight the design of submission signals and how such signals can reduce costs. Animal societies necessitate frequent social interactions, which can increase the probability of conflict. Where maintaining group proximity is essential, animals cannot avoid aggression by fleeing. Mutual interest between group members may also select for efficient conflict avoidance and resolution mechanisms. As a result, submission signals may be especially well developed among group living species, helping social animals to overcome potential costs of recurring conflict that could otherwise counter the benefits of group living. Therefore, submission signalling can be a crucial aspect of social living and is deserving of specific attention within the broader context of social evolution and communication.

Long-Term Colony Dynamics and Fitness in a Colonial Tent-Web Spider Cyrtophora citricola

Social animals are expected to experience a positive effect of conspecific number or density on fitness (an Allee effect) because of the benefits of group living. However, social animals also often disperse to live either solitarily or in small groups, so to understand why social animals leave their groups it is necessary to understand how group size affects both average fitness and the expected fitness outcomes of individuals. We examined the relationships between group size and fitness in the colonial spider Cyrtophora citricola using long-term observations of colony demographics. We censused colonies, recording the number of juveniles, large females, and egg sacs, approximately every 2 months for 2 years. We also recorded the substrates supporting colony webs, including plant species and size, and the azimuth the colony occupied on the plant. Colonies in all regions showed cyclical patterns of growth and decline; however, regions were not synchronized, and seasonal effects differed between years. Colonies with fewer individuals at the initial observation were less likely to survive over the course of observations, and extinction rates were also influenced by an interaction between region and plant substrate. Small colonies were more likely to be extinct by the next census, but if they survived, they were more likely to have high growth rates compared to larger colonies. Despite the potential for high growth rates, high extinction rates depressed the average fitness of small colonies so that population growth rates peaked at intermediate colony sizes. Variance in egg sac production also peaked at intermediate colony sizes, suggesting that competitive interactions may increase the uneven distribution of resources in larger groups. Even if average fitness is high, if spiders can anticipate poor outcomes in large colonies, they may disperse to live solitarily or in smaller, less competitive groups.