Conflict and Choice Time

Four variables have been suggested as determinants of degree of conflict: (1) number, (2) nearness to equality in strength, (3) absolute strength, and (4) degree of incompatibility, of competing response tendencies. first two, but not others, have figured in investigations relating reaction time to information theory. Three experiments were carried out to test effects of all these variables on choice time. Two types of choice RT were recorded: first, forced‐choice RT (i.e. traditional choice RT), for which one stimulus was presented at a time, each stimulus having its appropriate response; and second, free‐choice RT, for which two or more stimuli were presented together, S having to respond to any one of them. principal findings were as follows. (1) Both types of choice RT were longer when number of alternative responses was increased. (2) Free‐choice RT's were invariably longer than forced‐choice RT's, confirming influence of equality of strength. (3) Forced‐choice RT's were inversely related to stimulus intensity, which was regarded as a factor influencing absolute strength of response tendencies. Free‐choice RT's were shortest at intermediate of three intensity levels studied and significantly longer at highest and lowest levels. proportion by which free‐choice RT's exceeded forced‐choice RT's increased with stimulus intensity. (4) Degree of physiological incompatibility did not affect free‐choice RT's, although physiologically incompatible responses produced longer forced‐choice RT's. (5) There were no significant differences between RT's of S's with high and low neuroticism scores. expediency of continuing to include degree of physiological incompatibility among determinants of degree of conflict is called in question by results. Otherwise, choice time, apart from time taken up by eye movements, etc., which may be shorter with more intense stimuli, appears to increase with degree of conflict. results are discussed in light of various theoretical models, derived from Hull's principle of behavioural oscillation, Miller's theory of conflict, information theory, and Hebb's theory of cortical disruption.