Are there Nonverbal Cues to Commitment? An Exploratory Study Using the Zero-Acquaintance Video Presentation Paradigm

Altruism is difficult to explain evolutionarily if subtle cheaters exist in a population ( Trivers, 1971 ). A pathway to the evolutionary maintenance of cooperation is nonverbal altruist-detection. One adaptive advantage of nonverbal altruist-detection is the formation of trustworthy division of labour partnerships ( Frank, 1988 ). Three studies were designed to test a fundamental assumption behind altruistic partner preference models. In the first experiment perceivers (blind with respect to target altruism level) made assessments of video-clips depicting self-reported altruists and self-reported non-altruists. Video-clips were designed with attempts to control for attractiveness, expressiveness, role-playing ability, and verbal content. Overall perceivers rated altruists as more “helpful” than non-altruists. In a second experiment manipulating the payoffs for cooperation, perceivers (blind with respect to payoff condition and altruism level) assessed altruists who were helping others as more “concerned” and “attentive” than non-altruists. However perceivers assessed the same altruists as less “concerned” and “attentive” than non-altruists when the payoffs were for self. This finding suggests that perceivers are sensitive to nonverbal indicators of selfishness. Indeed the self-reported non-altruists were more likely than self-reported altruists to retain resources for themselves in an objective measure of cooperative tendencies (i.e. a dictator game). In a third study altruists and non-altruists' facial expressions were analyzed. The smile emerged as a consistent cue to altruism. In addition, altruists exhibited more expressions that are under involuntary control (e.g., orbicularis oculi) compared to non-altruists. Findings suggest that likelihood to cooperate is signaled nonverbally and the putative cues may be under involuntary control as predicted by Frank (1988) .

EFFECT OF ASSET VALUE CORRELATION ON CREDIT-LINKED NOTE VALUES

This paper develops a simple model to study the credit risk premiums of credit-linked notes using the structural model. Closed-form solutions of credit risk premiums of the credit-linked notes derived from the model as functions of firm values and the short-term interest rate, with time-dependent model parameters governing the dynamics of the firm values and interest rate. The numerical results show that the credit spreads of a credit-linked note increase non-linearly with the decrease in the correlation between the asset values of the note issuer and the reference obligor when the final payoff condition depends on the asset values of the note issuer and the reference obligor. When the final payoff condition depends on the recovery rate of the note issuer upon default, the credit spreads could increase with the correlation. In addition, the term structures of model parameters and the correlations involving interest rate are clearly the important factors in determining the credit spreads of the notes.

Influence of Different Preparatory Sets on Reaction Time and Arm-Movement Time

The effect of three different preparatory sets on reaction time (RT), movement time (MT) and reaction time-movement time (RT-MT) relationship was examined. All 15 subjects were required to perform under the three conditions regarding the relative payoff of stimulus and speed of movement. No significant effect on RT was found, while the significant difference between MT under MT-payoff condition and MT under RT-payoff condition was found. The correlations between RT and MT under MT-payoff condition and RT-MT-payoff condition are significant ( p < .05). Also high canonical correlation between RTs and MTs was found. Results suggested that the motor program in the simple task may be executed more effectively under MT-payoff condition than RT-payoff conditions and also that a certain amount of generality between RT and MT under the payoff conditions might exist in multivariate domains.

The Effects of Payoff on the Visual Processing of Dental Radiographs

The objective of the present study was to reassess the magnitude of observer error by dental students observing dental radiographs. Additionally, the effects of different payoff conditions on observer responses were examined. These data indicated high false positive rates as well as an inability to judge which radiographs were most difficult to assess. Further analyses indicated that false positive rates remained high even when payoff conditions penalized such responses. A payoff condition specifically designed to lower the false positive rate instead resulted in subjects lowering their hit rate and thus raising the miss rate. It is apparent that control of observer error must not only consider the technical quality of the radiograph but also the decision processes of the observer.

Investigation of Reading Strategies: II. A Replication of Payoff Condition Effects

An earlier study by McConkie and Rayner (1974) was replicated in which reading strategies of college students were manipulated through the use of payoff conditions. The influence of four variables on reading speed and test performance was investigated: existence of a payoff structure, the form of the payoff structure, type of payoff, and presence or absence of feedback. Essential characteristics of the earlier study were replicated. The existence of a payoff structure had little effect by itself, but the form of the structure produced significant changes in reading rate. Feedback on performance appears critical in producing substantial reading strategy changes in readers.

Effect of Payoffs for Consistency on Judgments of Preference and Complexity

The performance of Ss receiving explicit payoffs for high inter-session correlations on a task of ranking visual patterns for complexity and preference was compared with that of a no-payoff group. Inter-session correlations for both types of judgment did not differ significantly between the two groups. The payoff Ss showed higher concordance for preference judgments but not for complexity judgments. Control groups required to memorize an arbitrary order of patterns under either a payoff or no-payoff condition did worse than either experimental group. Preferences for payoff Ss were directly related to complexity in that simpler patterns were preferred; no such relationship was observed for the no-payoff Ss. Two interpretations of the results are discussed.