Effects Of Social Interactions Research Articles

Managing a service system with social interactions: Stability and chaos

This paper investigates the dynamic behavior of a service system in terms of the arrival rate in the steady state under the influence of social interactions. Customers are backward looking and rational when making purchasing decisions. Existing customers’ re-purchasing decisions are based on their experienced utility – a function of the average waiting time and their expected utility. Potential customers are attracted through social interactions with existing customers. It is shown that the arrival rate of the system in the steady state can exhibit stability, periodic cycles, or chaos due to the effect of social interactions and customers’ purchasing behavior. Two examples based on an M/M/1 queueing system illustrate the role of social interactions and the effect of service rates on the stability of the arrival rate in the steady state. The result highlights the dynamical complexity of a simple service system under the impact of customers’ behavioral factors, or social interactions. It suggests a new perspective to managing service operations whereby social interactions may play a critical role in the fluctuations of demand.

Financial literacy, information flows, and caste affiliation: Empirical evidence from India

This paper empirically investigates the relevance of social interaction and caste affiliation for individual awareness of financial instruments and investment behavior of households in India. The results of our empirical analysis, which is based on a large scale survey on saving patterns of Indians, suggest a positive relationship between financial literacy and social interaction. However, especially backward caste people living in regions with a large fraction of backward castes have a lower probability of being aware of various financial instruments. In contrast, we find only weak empirical evidence for a direct effect of caste affiliation and social interaction on investment behavior.

The effects of potential social interactions and implied social presence on social attention

The effects of potential social interactions and implied social presence on social attention

The Potential Effects of Social Interactions on Reproductive Efficiency of Stallions

The reproductive efficiency of stabled domestic stallions is often lower than what could be expected from observations in feral herds. In the wild, stallions typically live with mares in harem bands, with other stallions in bachelor bands, or occasionally in mixed-sex transitional bands. We, therefore, argue that permanent contact with mares may increase reproductive efficiency of stallions suffering from low libido and/or fertility. We also provide a summary of our present knowledge of natural conditions, management, and husbandry of domestic stallions, and of intra- and intersexual behavioral interactions in horses.

The heterogeneous spatial and temporal patterns of behavior of small pelagic fish in an array of Fish Aggregating Devices (FADs)

Identifying spatial and temporal patterns in fish movements can reveal the driving factors that govern the behavior of fish in their environment. In this study, we characterized the spatial and temporal occupation of 37 acoustically tagged bigeye scads (Selar crumenophthalmus) in an array of shallow Fish Aggregating Devices (FADs) to clarify the mechanism that leads fish to associate with FADs. A comparison of the number of visits and residence times exhibited by the fish at different FADs revealed a strong variability over the array of FADS, with the emergence of a leading FAD that recorded the majority of visits and retained the fish for a longer period of time. We found diel variability in the residence times, with fish associated at daytime and exploring the array of FADs at nighttime. We demonstrated that this diel temporal pattern was amplified in the leading FAD. We identified a 24-hour periodicity for a subset of individuals associated to the leading FAD, thus suggesting that those fish were able to find this FAD after night excursions. The modeling of fish movements based on a Monte Carlo sampling of inter-FAD transitions revealed that the observed spatial heterogeneity in the number of visits could not be explained through simple array-connectivity arguments. Similarly, we demonstrated that the high residence times recorded at the leading FAD were not due to the spatial arrangement of individual fish having different associative characters. We discussed the relationships between these patterns of association with the FADs, the exploration of the FAD array and the possible effects of social interactions and environmental factors.

The ecology of stress: effects of the social environment

Summary Many aspects of the social environment affect hypothalamic‐pituitary‐adrenal (HPA) axis function and increase circulating glucocorticoid concentrations. In this review, we examine the relationships between the social environment and the function of the HPA axis in vertebrates. First, we explore the effects of the social environment on glucocorticoid secretion in territorial (primarily non‐social) species, with an emphasis on the effects of variation in population density, as modified by environmental factors such as predation risk and food availability. In general, high population density or frequent territorial intrusions are associated with increased glucocorticoid secretion in a wide range of taxa, including mammals, birds, fish and reptiles, although there is considerable variability across species. Second, we consider the effects of social interactions and dominance rank on glucocorticoid secretion in social species, mostly in birds and mammals. We review studies that have detected an association between social status and glucocorticoid levels – sometimes with higher glucocorticoid levels in low‐ranking individuals, and sometimes with higher glucocorticoid levels in dominant individuals. The relationship between dominance and glucocorticoid levels varies among species, populations and years, in a manner that depends on the stability of the social hierarchy, environmental conditions, the type of breeding system, and the manner in which high rank is obtained and maintained. Finally, we discuss the concept of allostasis and consider interactions between social effects and other environmental factors, noting that there is relatively little research on these interactions to date. For both non‐social and social species, we identify priorities of future research. These priorities include more complete descriptions of HPA function that move beyond measurements of basal glucocorticoid concentrations (which will generally require field experiments), to studies that examine organizational effects of social stressors, that directly test the relationship between HPA function and fitness, and that examine how glucocorticoid responses affect population dynamics. Although several lines of evidence suggest that glucocorticoid responses can affect the fitness of individuals and therefore can alter the dynamics of populations, the effect of glucocorticoid responses on population dynamics remains essentially unstudied.

A Comparison of Solo and Multiplayer Active Videogame Play in Children with Unilateral Cerebral Palsy.

Active videogames (AVGs) have potential in terms of physical activity and therapy for children with cerebral palsy. However, the effect of social interaction on AVG play has not yet been assessed. The objective of this study is to determine if multiplayer AVG versus solo affects levels of energy expenditure and movement patterns. Fifteen children (9.77 [standard deviation (SD) 1.78] years old) with hemiplegic cerebral palsy (Gross Motor Function Classification System Level I) participated in solo and multiplayer Nintendo(®) "Wii™ Boxing" (Nintendo, Inc., Redmond, WA) AVG play while energy expenditure and punching frequency were monitored. Moderate levels of physical activity were achieved with no significant differences in energy measures during multiplayer and solo play. Dominant arm punching frequency increased during the multiplayer session from 95.75 (SD 37.93) punches/minute to 107.77 (SD 36.99) punches/minute. Conversely, hemiplegic arm punching frequency decreased from 39.05 (SD 29.57) punches/minutes to 30.73 (SD 24.74) punches/minutes during multiplayer game play. Children enjoyed multiplayer more than solo play. Opportunities to play AVGs with friends and family may translate to more frequent participation in this moderate physical activity. Conversely, increased hemiplegic limb use during solo play may have therapeutic advantages. As such, new strategies are recommended to promote use of the hemiplegic hand during multiplayer AVG play and to optimize commercial AVG systems for applications in virtual reality therapy.

The People in Your Neighborhood: Social Interactions and Mutual Fund Portfolio Choice

We find that socially connected fund managers have more similar holdings and trades. The portfolio overlap of funds whose managers reside in the same neighborhood is considerably higher than that of funds whose managers live in the same city but in different neighborhoods. These effects are larger when managers are neighbors longer or are of a similar ethnic background, and are not explained by preferences. Valuable information is transmitted through these peer networks: a long-short strategy composed of stocks purchased minus sold by neighboring managers delivers positive risk-adjusted returns. Unlike prior empirical work, our tests disentangle the effects of social interactions from community effects.

Peer Effects in the Diffusion of Solar Photovoltaic Panels

Social interaction (peer) effects are recognized as a potentially important factor in the diffusion of new products. In the case of environmentally friendly goods or technologies, both marketers and policy makers are interested in the presence of causal peer effects as social spillovers can be used to expedite adoption. We provide a methodology for the simple, straightforward identification of peer effects with sufficiently rich data, avoiding the biases that occur with traditional fixed effects estimation when using the past installed base of consumers in the reference group. We study the diffusion of solar photovoltaic panels in California and find that at the average number of owner-occupied homes in a zip code, an additional installation increases the probability of an adoption in the zip code by 0.78 percentage points. Our results provide valuable guidance to marketers designing strategies to increase referrals and reduce customer acquisition costs. They also provide insights into the diffusion process of environmentally friendly technologies.

Why, when, and how fast innovations are adopted

When the full stock of a new product is quickly sold in a few days or weeks, one has the impression that new technologies develop and conquer the market in a very easy way. This may be true for some new technologies, for example the cell phone, but not for others, like the blue-ray. Novelty, usefulness, advertising, price, and fashion are the driving forces behind the adoption of a new product. But, what are the key factors that lead to adopt a new technology? In this paper we propose and investigate a simple model for the adoption of an innovation which depends mainly on three elements: the appeal of the novelty, the inertia or resistance to adopt it, and the interaction with other agents. Social interactions are taken into account in two ways: by imitation and by differentiation, i.e., some agents will be inclined to adopt an innovation if many people do the same, but other will act in the opposite direction, trying to differentiate from the "herd". We determine the conditions for a successful implantation of the new technology, by considering the strength of advertising and the effect of social interactions. We find a balance between the advertising and the number of anti-herding agents that may block the adoption of a new product. We also compare the effect of social interactions, when agents take into account the behavior of the whole society or just a part of it. In a nutshell, the present model reproduces qualitatively the available data on adoption of innovation.

The effect of social interaction on learning engagement in a social networking environment

This study investigated the impact of social interactions among a class of undergraduate students on their learning engagement in a social networking environment. Thirteen undergraduate students enrolled in a course in a university in Hong Kong used an Elgg-based social networking platform throughout a semester to develop their digital portfolios and interact with each other. Student online activities were analyzed using content analysis and descriptive statistics with social network analysis. The findings suggest that the social interaction afforded by a social networking environment was short-lived, individual-centered and casual. Communication skills and autonomy on the part of students are required to foster communication. The study further revealed that while such social patterns in the social networking environment appeared to enhance social engagement, a high level of cognitive engagement was not demonstrated. Recommendations are made in relation to the effective utilization of a social networking platform to support productive and meaningful learning.

Separating Contextual from Endogenous Effects in Automobile Ownership Models

Using the 1997/98 New York Metropolitan Transportation Council household survey and United States Census, we estimate an instrumental variable probit model to test the impact of contextual and endogenous social interaction effects on auto ownership and determine that the probability of car ownership is affected by both types of social interaction effects. Previous research focused only either on contextual effects, or, increasingly, on endogenous effects using contextual effects variables as instruments. Therefore we were unable to find studies looking at both social interaction effects simultaneously. Consistent with earlier results, we find that households have a higher probability of possessing a vehicle if they are surrounded by other automobile-owning households (endogenous effect). However, we find that contextual effects are correctly measured only when the endogenous effect is included. In our case, everything else being equal, households in poorer neighborhoods are more likely to own vehicles, and households in neighborhoods with higher proportions of people with graduate degrees are less likely to own vehicles. This suggests that car ownership in New York City is a status symbol for poorer households and that non-car-ownership is a status symbol for people with post baccalaureate education. The results are important in two policy contexts: as auto ownership is a precursor to trip generation and mode choice, auto ownership estimation is important to effective travel forecasting; as vehicle miles traveled (VMT) is tied to auto ownership, VMT reduction strategies, as a way to improve air quality, reduce congestion, and reduce greenhouse gas emissions, may depend on strategies to reduce auto ownership. In either case, correct modeling of auto ownership will lead to more effective policy outcomes.

What Is the Brain-Cancer Connection?

A focus of much cancer research is at the molecular and cellular levels. In contrast, the effects of social interactions and psychological state are less investigated, and considered by many a "soft" science. Yet several highly rigorous studies have begun to tease out biochemical pathways by which the brain can influence the development and growth of cancer. Previous reviews have discussed the concept of stress and cancer. Here, we discuss recent work showing environments that are more complex and challenging, but not stressful per se, and that have robust effects on peripheral cancer by activating a specific neuroendocrine brain-adipocyte axis. These enriched environments lead to activation of the sympathetic innervation of fat tissue, suppression of leptin, and a reduction in cancer proliferation by inducing hypothalamic BDNF expression. We summarize this work and discuss how these data integrate into the body of literature regarding stress, the environment, and cancer.

Aggregation in woodlice: social interaction and density effects

Terrestrial isopods are known to be sensitive to humidity, brightness or temperature. Until now, aggregation was assumed to depend on these sensitivities as a result of individual preferences. In this paper, we show that the social component is also important in the isopod aggregation phenomenon. In experimental arenas with two identical shelters up to nearly 90% of woodlice aggregated under shelters. This aggregation was quick as in 10 minutes most of the animals aggregated, irrespective of their density. Nonetheless, 10–15% of the animals walked around the arena, rarely forming very small and short-lasting aggregates outside shelters. Woodlice aggregated preferably under one of the shelters in 77% of experiments. Indeed, almost 80% of the animals out of 40, 60 or 80 animals in the arena aggregated under one shelter. In arenas with 100 individuals the aggregations were proportionally smaller (70%). Our results revealed that 70 animals was a maximum number of woodlice in an aggregate. We concluded that the location of aggregates is strongly governed by individual preferences but the dynamics of aggregation and collective choice are controlled by social interaction between congeners. The tested densities of the animals in the arena did not impact the aggregation patterns.

Household Debt and Social Interactions

Can concern with relative standing, which has been shown to influence consumption and labor supply, also increase borrowing and the likelihood of financial distress? We find that perceived peer income contributes to debt and the likelihood of financial distress among those who consider themselves poorer than their peers. We use unique responses describing perceived peer characteristics from a Dutch population-wide survey to handle major challenges of uncovering social interaction effects on borrowing: (i) debts, unlike conspicuous consumption, are often hidden from peers, and (ii) location is missing in anonymized data. We employ several approaches to uncover exogenous, rather than correlated, effects.

Modified Penna bit-string network evolution model for scale-free networks with assortative mixing

Motivated by biological aging dynamics, we introduce a network evolution model for social interaction networks. In order to study the effect of social interactions originating from biological and sociological reasons on the topological properties of networks, we introduce the activitydependent rewiring process. From the numerical simulations, we show that the degree distribution of the obtained networks follows a power-law distribution with an exponentially decaying tail, P(k) ∼ (k + c)−γ exp(−k/k 0). The obtained value of γ is in the range 2 < γ s 3, which is consistent with the values for real social networks. Moreover, we also show that the degree-degree correlation of the network is positive, which is a characteristic of social interaction networks. The possible applications of our model to real systems are also discussed.

School for learning: sharing and transmission of feeding information in jack mackerel Trachurus japonicus juveniles

We aimed to evaluate the effect of social interaction on learning in juvenile jack mackerel Trachurus japonicus. We first compared the learning process between single fish and groups of fish. Reward-conditioned learning was established in eight trials in both treatments, whereas individuals in the group treatment responded to stimuli more frequently in the feeding area than in the single fish. This implies that information about the feeding area was shared in the group and pursuing other individuals gave them a behavioral advantage for feeding. We then investigated whether information on the feeding area can be transmitted through observation of other individuals in aligned tanks. Fish in the control group required six trials to be conditioned to aeration stimuli and feeding location, whereas those in the observation treatment required only three trials for this learning. This result implies that information on the feeding area was transmitted through visual observations. The present research suggests that sharing and transmission of information occur in schools of jack mackerel. Schooling behavior would thus enable optimization of the foraging behavior in this species.

Identification of Interaction Effects in Survey Expectations: A Cautionary Note

A growing body of literature reports evidence of social interaction effects in survey expectations. In this note, we argue that evidence in favor of social interaction effects should be treated with caution, or could even be spurious. Utilizing a parsimonious stochastic model of expectation formation and dynamics, we show that the existing sample sizes of survey expectations are about two orders of magnitude too small to reasonably distinguish between noise and interaction effects. Moreover, we argue that the problem is compounded by the fact that highly correlated responses among agents might not be caused by interaction eects at all, but instead by model-consistent beliefs. Ultimately, these results suggest that existing survey data cannot facilitate our understanding of the process of expectations formation.

Preventive role of social interaction for cocaine conditioned place preference: correlation with FosB/DeltaFosB and pCREB expression in rat mesocorticolimbic areas.

The worsening of drug abuse by drug-associated social interaction is a well-studied phenomenon. In contrast, the molecular mechanisms of the beneficial effect of social interaction, if offered as a mutually exclusive choice to drugs of abuse, are under-investigated. In a rat place preference conditioning (CPP) paradigm, four 15 min episodes of social interaction with a gender- and weight-matched male early-adult conspecific inhibited cocaine-induced reinstatement of cocaine CPP, a model of relapse. These protective effects of social interaction were paralleled by a reduced activation, as assessed by Zif268 expression, in brain areas known to play pivotal roles in drug-seeking behavior. Here we show that social interaction during extinction of cocaine CPP also reduced cocaine-CPP-stimulated FosB expression in the nucleus accumbens shell and core. In addition, social interaction during cocaine CPP extinction increased pCREB (cAMP response element binding protein) expression in the nucleus accumbens shell and the cingulate cortex area 1 (Cg1). Our results show that FosB and pCREB may be implicated in the protective effect of social interaction against cocaine-induced reinstatement of CPP. Thus, social interaction, if offered in a context that is clearly distinct from the previously drug-associated one, may profoundly inhibit relapse to cocaine addiction.

Social Interaction Effects and Individual Portfolio Choice: Evidence from 401(K) Pension Plan Investors

Social Interaction Effects and Individual Portfolio Choice: Evidence from 401(K) Pension Plan Investors