Matching Items (16)

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Registered Replication Report: Rand, Greene, & Nowak

Description

In an anonymous 4-person economic game, participants contributed more money to a common project (i.e., cooperated) when required to decide quickly than when forced to delay their decision (Rand, Greene

In an anonymous 4-person economic game, participants contributed more money to a common project (i.e., cooperated) when required to decide quickly than when forced to delay their decision (Rand, Greene & Nowak, 2012), a pattern consistent with the social heuristics hypothesis proposed by Rand and colleagues. The results of studies using time pressure have been mixed, with some replication attempts observing similar patterns (e.g., Rand et al., 2014) and others observing null effects (e.g., Tinghög et al., 2013; Verkoeijen & Bouwmeester, 2014). This Registered Replication Report (RRR) assessed the size and variability of the effect of time pressure on cooperative decisions by combining 21 separate, preregistered replications of the critical conditions from Study 7 of the original article (Rand et al., 2012). The primary planned analysis used data from all participants who were randomly assigned to conditions and who met the protocol inclusion criteria (an intent-to-treat approach that included the 65.9% of participants in the time- pressure condition and 7.5% in the forced-delay condition who did not adhere to the time constraints), and we observed a difference in contributions of −0.37 percentage points compared with an 8.6 percentage point difference calculated from the original data. Analyzing the data as the original article did, including data only for participants who complied with the time constraints, the RRR observed a 10.37 percentage point difference in contributions compared with a 15.31 percentage point difference in the original study. In combination, the results of the intent-to-treat analysis and the compliant-only analysis are consistent with the presence of selection biases and the absence of a causal effect of time pressure on cooperation.

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Agent

Created

Date Created
  • 2017-03-01

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Responses to Cheating in Need-Based Transfers: An Agent Based Model

Description

Gift-giving economies are economic models that freely give resources rather than barter for them or purchase them from market. Need-based transfers fit into this economic model by freely giving resources

Gift-giving economies are economic models that freely give resources rather than barter for them or purchase them from market. Need-based transfers fit into this economic model by freely giving resources on the basis of need, provided the giver can spare the resources. The Maasai are an East African pastoral tribe that practices need-based transfers through a tradition they call osotua. If they have a partner with an established osotua relationship, then they will give any amount of cattle that partner request, provided they can spare the cattle. Cheating each other is unheard of in this tradition, but for this simulation I am introducing cheating into this economic model through feigning need. If a cheater is not in need, they will act like they are in need. If they are in need, then the cheater will request more cattle than what they need to survive. I am testing two different responses to cheating: walking-away and punishing. In the walk-away condition, the victim ends their osotua partnership and establishes a new one. In the punishment condition, a portion of the cheater's stolen cattle is destroyed.

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Agent

Created

Date Created
  • 2016-12

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Attitudes toward asking for help: Effects of Perceived Social Status on help-seeking behaviors

Description

Humans engage in many forms of cooperation within social groups, creating the ability for people help others when they are in need. One specific type of cooperation helps alleviate need

Humans engage in many forms of cooperation within social groups, creating the ability for people help others when they are in need. One specific type of cooperation helps alleviate need and manage risk in both kin and non-kin relationships. However, how people ask for help or notice when someone else is in need have not received systematic investigation. In this study, participants’ self-reported socioeconomic status (SES) was collected along with information about their willingness to engage in a variety of help-seeking behaviors in certain situations. Participants’ general emotions and attitudes associated with certain aspects of asking for help were also collected. It was predicted that people with lower SES would be more reluctant to ask due to more negative emotions associated with and more instances of needing to ask for help. People with higher SES were predicted to be more likely to ask for help due to fewer negative emotions associated with asking and less need to ask for help overall. We found that people with lower SES were generally less willingness to engage in help-seeking behaviors compared to those of higher SES. However, results did not support the hypothesis that people with lower SES would experience more negative emotions associated with asking for help. Considering these results, further studies should investigate willingness to seek financial help versus other types of help in personal relationships and from institution-based assistance programs. Future research should also seek to determine how feelings of entitlement in individuals with higher SES affect willingness to ask for and offer help.

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Agent

Created

Date Created
  • 2020-05

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Mathematical Modeling of Foundress Associations in Social Insects in Order to Understand Aggression in Cooperative Social Systems

Description

This project aims to better understand aggression in a cooperative social system, specifically within the ant species Pogonomyrmex Californicus. The queens of some populations of these ants form cooperative associations

This project aims to better understand aggression in a cooperative social system, specifically within the ant species Pogonomyrmex Californicus. The queens of some populations of these ants form cooperative associations of unrelated queens during nest foundation, while others prefer to form solitary nests and may show aggression towards unwanted nest mates. Because it is difficult to collect large amounts of data from a wild population and laboratory environments cannot capture the scale of nature, we created a computer simulation based on data collected in the lab and the field that emulates the life cycle of this species of ants. By manipulating behavioral and environmental conditions and observing the results we were able to better understand the advantages and disadvantages of showing aggression in this cooperative social system.

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Created

Date Created
  • 2016-05

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Variation in Growth Rate of Colonies with Differing Queen Systems in the Ant Species Pogonomyrmex californicus

Description

I tested the hypothesis that in mature colonies of the seed harvester Pogonomyrmex californicus ant species, paired pleometrotic queens would produce workers more efficiently after a massive removal of their

I tested the hypothesis that in mature colonies of the seed harvester Pogonomyrmex californicus ant species, paired pleometrotic queens would produce workers more efficiently after a massive removal of their work force than haplometrotic queens, paired pleometrotic with haplometrotic queens, and single pleometrotic queens. I suggested that the paired pleometrotic queens would have an advantage of cooperating together in reproducing more workers quicker than the other conditions to make up for the lost workers. This would demonstrate a benefit that pleometrosis has over haplometrosis for mature colonies, which would explain why pleometrosis continues for P.californicus after colony foundation. After removing all but twenty workers for every colony, I took pictures and counted the emerging brood for 52 days. Analyses showed that the paired pleometrotic queens and the haplometrotic queens both grew at an equally efficient rate and the paired pleometrotic and haplometrotic queens growing the least efficiently. However, the results were not significant and did not support the hypothesis that paired pleometrotic queens recover from worker loss more proficiently than other social systems.

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Agent

Created

Date Created
  • 2014-05

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Quantifying Cost Savings of Pleometrosis and Haplometrosis: Excavation Labor of the Seed-HArvester Ant Pogonomyrmex californicus

Description

Studies of cooperation remain an important aspect in understanding the evolution of social cues and interactions. One example of cooperation is pleometrosis, an associative behavior of forming a colony with

Studies of cooperation remain an important aspect in understanding the evolution of social cues and interactions. One example of cooperation is pleometrosis, an associative behavior of forming a colony with two unrelated, fertile queens. However, most ant species display haplometrosis, the founding of a colony by a single queen. In these associations, the queen typically rejects cooperation. In populations of Pogonomyrmex californicus, both pleometrosis and haplometrosis exists. It is not clear how associative -metrosis became a practiced behavior since haplometrotic queens tend to fight. However, as fighting in pleometrotic queens became less frequent, this induces benefit, in terms of cost savings, in having associative behaviors. The hypothesis tested was nest excavation of pleometrotic queens show sociality, while haplometrotic queens show association independence. Isolated pleometrotic queens (P) showed low excavation rate at 2.72cm2/day, compared to the rate when the task was shared in (PP) nests, 4.57cm2/day. Nest area of the (P) queens were also affected during days 3 and 4 of the experiment, where there was presence of nest area decrease. Furthermore, the excavation session of (P) was the only one determined as significant between all other nests. Although the (P) queens have low values, they eventually reach a similar point as the other nests by day 6. However, the lack of haste in excavation leads to longer exposure to the elements, substituting the risk of losing cuticles in excavation for the risk of predation. For the haplometrotic queens, nests of (H) and (HH) displayed no significant difference in excavation values, leading to having social effect in their association.

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Agent

Created

Date Created
  • 2019-05

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Does Sharing Food Influence Trust and Interdependence?

Description

Food-sharing is central to the human experience, involving biological and sociocultural functions. In small-scale societies, sharing food reduces variance in daily food-consumption, allowing effective risk-management, and creating networks of interdependence.

Food-sharing is central to the human experience, involving biological and sociocultural functions. In small-scale societies, sharing food reduces variance in daily food-consumption, allowing effective risk-management, and creating networks of interdependence. It was hypothesized that trust and interdependence would be fostered between people who shared food. Recruiting 221 participants (51% Female, Mage = 19.31), sharing food was found to decrease trust and interdependence in a Trust Game with $3.00 and a Dictator Game with chocolates. Participants trusted the least and gave the fewest chocolates when sharing food. Contrary to lay beliefs about sharing food, breaking bread with strangers may hinder rather than foster trust and giving in situations where competition over limited resources is salient, or under one-shot scenarios where people are unlikely to see each other again in the future.

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Agent

Created

Date Created
  • 2020

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Friendship Jealousy: An (Overlooked) Emotion for Friendship Maintenance?

Description

Friendships make us happy, keep us healthy, and can even facilitate our reproductive fitness. But most friendships are not forever—even when we want them to be. How do people maintain

Friendships make us happy, keep us healthy, and can even facilitate our reproductive fitness. But most friendships are not forever—even when we want them to be. How do people maintain valued friendships? I propose that “friendship jealousy” arises when people perceive others as posing threats to valued friendships, and that this response can function to prevent friendship loss and friend defection. In preliminary experiments, I tested predictions derived from this functional view. As predicted, I found, first, that friendship jealousy is calibrated to friend value. Second, friendship jealousy predicts intentions to “friend guard” (i.e., engage in behavior to protect the friendship). Third, friendship jealousy has sex-differentiated features, which are consistent with sex differences in friendship structures and ancestral friendship functions. The present work pits against one another intuitive and functional predictions as to what drives friendship jealousy. Although intuition might lead one to expect greater jealousy when a friend spends more time with a new person, a functional view suggests greater jealousy when that new person threatens to fulfill the same function for one’s friend that one is currently fulfilling (i.e., to “replace” him/her). Preliminary studies revealed that greater friendship jealousy is evoked when friends form new same-sex friendships (which presumably pose greater replacement threat, but lesser time threat) versus new romantic relationships (which presumably pose lesser replacement threat, but greater time threat). The focal experiment explicitly and experimentally manipulates a version of “replacement threat” (whether the best friend “chooses” the new friend over you) and “time threat” (how much time the best friend spends with the new friend). In line with functional predictions, the amount of time the best friend spends with a new friend drives friendship jealousy—but only when direct information about replacement threat is unavailable. Regardless of the time threat posed, participants report high friendship jealousy when replacement threat is high, and low friendship jealousy when replacement threat is low. Results imply that friendship jealousy is calibrated to replacement threat (over time threat). Overall, findings suggest that friendship jealousy might be a functional response aimed at facilitating friendship maintenance.

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Agent

Created

Date Created
  • 2018

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A novel approach to study task organization in animal groups

Description

A key factor in the success of social animals is their organization of work. Mathematical models have been instrumental in unraveling how simple, individual-based rules can generate collective patterns via

A key factor in the success of social animals is their organization of work. Mathematical models have been instrumental in unraveling how simple, individual-based rules can generate collective patterns via self-organization. However, existing models offer limited insights into how these patterns are shaped by behavioral differences within groups, in part because they focus on analyzing specific rules rather than general mechanisms that can explain behavior at the individual-level. My work argues for a more principled approach that focuses on the question of how individuals make decisions in costly environments.

In Chapters 2 and 3, I demonstrate how this approach provides novel insights into factors that shape the flexibility and robustness of task organization in harvester ant colonies (Pogonomyrmex barbatus). My results show that the degree to which colonies can respond to work in fluctuating environments depends on how individuals weigh the costs of activity and update their behavior in response to social information. In Chapter 4, I introduce a mathematical framework to study the emergence of collective organization in heterogenous groups. My approach, which is based on the theory of multi-agent systems, focuses on myopic agents whose behavior emerges out of an independent valuation of alternative choices in a given work environment. The product of this dynamic is an equilibrium organization in which agents perform different tasks (or abstain from work) with an analytically defined set of threshold probabilities. The framework is minimally developed, but can be extended to include other factors known to affect task decisions including individual experience and social facilitation. This research contributes a novel approach to developing (and analyzing) models of task organization that can be applied in a broader range of contexts where animals cooperate.

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Agent

Created

Date Created
  • 2016

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Risk abatement practices of recipient participants in private arrangement milk sharing in the United States

Description

Exclusivity and duration of breastfeeding and the provision of human milk in the United States is suboptimal. In the absence of adequate banked donor human milk for distribution to all

Exclusivity and duration of breastfeeding and the provision of human milk in the United States is suboptimal. In the absence of adequate banked donor human milk for distribution to all infants in need, many families choose to engage in the practice of Private Arrangement Milk Sharing (PAMS), partially facilitated through social media, to procure human milk for their infants. Evidence regarding the participant and infant characteristics and risk abatement practices is incomplete. This dissertation describes and explores the characteristics of recipient participants and infants, family constellation, donor screening practices, and related risk abatement strategies. Data was collected via on-line survey as a sub-group of a larger data set including donor participants and international participants. Binary logistic regression modeling of factors that contribute to consistent screening and risk abatement practices and important antecedents to engaging in PAMS was conducted. Results are contextualized within a tailored socioecological framework of factors affecting infant feeding practices. Tailoring was accomplished via qualitative descriptive analysis of participant responses applied to an existing breastfeeding framework. Participants in this sample were predominantly white, married, with a mean age of 32.9 years, with at least some college education and above median income. Risk abatement and screening practices were influenced by support of a healthcare provider during decision-making, college education, infant age and health status, having lactation support, birth type and birth attendant, and the duration and sources sought for learning about milk sharing.

Contributors

Agent

Created

Date Created
  • 2016