Experimental manipulation of the vacillating—persisting tendency

This paper provides an analysis of the behavioural style of vacillation vs. persistence which underlies the concept of strength of will. Vacillation‐persistence was assumed to be associated with a phenomenological state called ‘self‐engagement’. In three experiments, manipulations of self‐engagement led to effects on a measure of task persistence, and results on a performance measure were systematically different from those on the task persistence measure. A fourth study showed task persistence to be correlated with post‐experimental reports of being excited by the task and doing the task in order to improve self‐perception. Alternative interpretations of these data based on intrinsic motivation theory are discussed. 1988 The British Psychological Society