Frank Tutzauer

The Persuasive Effects of Message Framing in Organ Donation: The Mediating Role of Psychological Reactance

The effects of message framing on reactions to campaign messages promoting organ donation were examined in three experiments. It was predicted that gain-framed messages would produce more positive reactions toward organ and tissue donation. In Study 1, students (N=189) responded to either a gain-framed or loss-framed message about organ donation. Study 2 (N=318) and Study 3 (N=433) examined the role of psychological reactance as a mediator between framing and reactions. Results indicated an effect for framing across the three studies—specifically, students reading a gain-framed message reported more favorable reactions toward the scripted message and lower psychological reactance. Psychological reactance and perceived manipulative intent were found to mediate the relationship between framing and message reactions.

Entropy as a measure of centrality in networks characterized by path-transfer flow

Abstract Recently, Borgatti [Borgatti, S.P., 2005. Centrality and network flow. Social Networks 27, 55–71] proposed a taxonomy of centrality measures based on the way that traffic flows through the network—whether over path, geodesic, trail, or walk, and whether by means of transfer, serial duplication, or parallel duplication. Most of the extant centrality measures assume that traffic propagates via parallel duplication or, alternatively, that it travels over geodesics. Few of the other flow possibilities have centrality measures associated with them. This article proposes an entropy-based measure of centrality appropriate for traffic that propagates by transfer and flows along paths. The proposed measure can be applied to most network types, whether binary or weighted, directed or undirected, connected or disconnected. The measure is illustrated on the gang alliance network of Kennedy et al. [Kennedy, D.M., Braga, A. A., Piehl, A.M., 1998. The (un)known universe: mapping gangs and gang violence in Boston. Crime Prevention Studies 8, 219–262].

Network structure, strategy evolution, and the game of Chicken

Abstract Cellular automata – lattice-like grids of interlinked cells – can be used to study system evolution. The cells are occupied by disputants with differing strategic interaction rules. After interacting, each disputant either retains its strategy or adopts that of a neighbor, depending on relative strategy success. In this article, we use networks to answer questions about strategy evolution in the game of Chicken. We identify the nodes of a network with cells of an automaton and consider nodes adjacent if they are neighboring cells in the automaton, allowing us to determine structural influences of strategy evolution.

Entropy-Based Centralization and its Sampling Distribution in Directed Communication Networks

This article proposes a new measure of network centralization and reports the results of a simulation designed to determine the sampling distribution of the proposed measure. The measure is based on the information-theoretic concept of entropy and is appropriate for those networks in which traffic flows over paths and propagates by means of transference. Tables of critical values are constructed which allow the researcher to conduct tests of significance.

A Matrix Approach to Generalizing Axelrod-Type Tournaments

Axelrods (1980a 1980b) Prisoners Dilemma computer tournaments have motivated numerous investigations of cooperation, strategy choice, and strategic evolution. By having players adopt various strategies for playing the Prisoners Dilemma, and then programming a computer to pit the strategies against each other in a round-robin format, Axelrod uncovered important principles about the evolution of cooperation in certain contexts, and stimulated others to extend his basic method into other settings. This article presents a matrix approach for calculating the results of an Axelrod-type tournament. This approach allows one to investigate the impact of changes in the format of the tournament, the nature of the payoff matrix, or the particular strategic choices of the players.