Date of Award


Degree Type


Degree Name

Doctor of Philosophy


A series of studies was carried out in order to determine the effects of choice availability on the magnitude of the stress response. Study One required subjects to rate the stressfulness of a number of imaginally-presented scenarios. The availability of roughly equivalent options did not affect perceived stressfulness relative to single-option conditions, whereas the availability of contrasting options was associated with reductions in rated stressfulness that could not be accounted for by instrumental effects. Study Two used similar conditions, and required subjects to select from an array of one or two volumes of white noise. Both psychophysiological and self-reported evidence of stress indicated greater arousal in anticipation of loud volumes than quiet volumes. The provision of two similar options had much the same effect as providing a single option, but the effect of contrasting options seen in Study One was not observed in this study.;Study Three used a questionnaire format similar to Study One, and compared conditions in which information regarding option effectiveness was either provided or withheld. When only one option was available, the provision of outcome information did not affect rated stressfulness. The availability of a choice between options had no effect when information was unavailable and resulted in lower stress ratings when it was available. Provision of greater than two options produced no further decrements in rated stressfulness. Study Four used the laboratory format of Study Two, and manipulated the number of options (two versus eight) and information availability. There was no effect of the number of options on physiological or self-report measures when information was unavailable or readily available, but when accessing the information entailed a small information processing load per option, greater choice was associated with greater arousal.;It is concluded that choice availability reduces stress levels primarily by enabling the selection of a less threatening outcome. Choice appears to have ameliorative effects only when the information upon which to base a selection is provided. Further, there is some evidence that increasing the number of options may actually increase arousal levels, particularly when each option imposes an information processing load.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.