On the regularity of smoking.

The purpose of this paper is to provide fundamental information about individual subject smoking behavior when the behavior is characterized as an event time-series. Each subject's smoking series revealed a characteristic inter-cigarette interval frequency distribution but there was little evidence of sequential dependencies in the series with respect to either successive intervals or successive events in time. Several subjects exhibited possible characteristic peaks or troughs during successive 2-hour periods, a finding which was in agreement with previous studies, but even in these subjects temporal patterning accounted for only a small proportion of the total variance. The implications of these findings are discussed and recommendations for the future treatment of smoking data and for possible experimental approaches to the determinants of smoking are presented.