# Trust Model of Privacy-Concerned, Emotionally Aware Agents in a Cooperative Logistics Problem
## 4 Proposed Trust Model  
Interactions between agents cause both rewards and punishments that strongly influence the ways in which agents trust each other. On one hand, the privacy concern caused by other agents (in the logistic problem, whenever our agent meets another agent in a sensible cell or with a sensible box) produces negative feedback (social punishment) in our agent. On the other hand, our agent receives positive feedback (social reward) when the task is successfully accomplished (in the logistic problem, when the box reaches the destination). If the moving of a box is partly delegated to other (trusted) agents, our agent receives a reward corresponding to the level of joint success of the trusted agents proportionally to the incurred delays in delivery. Therefore, we can now distinguish between two different rewards that agents receive: privacy-related rewards and the delay-related rewards, both of which can be further classified into two subtypes: those related to the box and place (privacy-related rewards) and those related the subject agent's performance and that of alien agents (delay-related rewards). We can distinguish between two different trusting decisions:  
1. The decision to request cooperation, where our agent becomes the trusting agent, as it delegates a task to another (trusted) agent, taking some risks (in our logistic problem, trusting another agent to move a box towards its destination), with no associated certainty or guarantee of the future behavior of the other agent, although afterward, the trusting agent receives delayed feedback about the behavior of the trusted agent (in our logistic problem, the trusting agent learns whether the box reached the destination in a given time or not). 2. The decision to answer a cooperation request from another agent, where our agent becomes the trusting agent, as it carries out a delegated task for other (trusted) agent, taking some risks (in our case, trusting the other agent to reach the destination in a given time). Again, there is no associated certainty or guarantee of the future behavior of the other agent, although afterward, the trusting agent receives delayed feedback about the behavior of the trusted agent (in our logistic problem, the trusting agent will learn whether the moving task was performed in time or not). The decision to request cooperation from another agent depends upon the following criteria:* The mood (current feeling) of the trusting agent: positive emotions (joy and surprise) of the agent encourage trusting decisions, whereas negative (sadness and fear) and antisocial (anger) emotions discourage trusting decisions, with a bonus/malus of 0.1 of trust required;
* The privacy issues of the agent involved in the trusting decision (in our logistic problem, the level of privacy associated with the box to be delegated). If privacy issues are involved, then 0.1 less trust is assigned to the other agent;
* How much the other agent is trusted: Trust is computed based the previous performance of the other agent in interactions with the subject agent (in our logistic problem, the level of previous success of the other agent performing moving tasks of the subject agent). Success (delivery of the box without delay) is associated with an increase of 0.1 in trust, whereas each cycle of delay translates to a \(-\)0.05 decrease in trust;
* How much the agent needs help (in our logistic problem, the number of boxes already carried): For each box already being carried, 0.05 less trust is assigned to the other agent.