Numerous theories in social and health psychology assume that intentions cause behaviours. However, most tests of the intention- behaviour relation involve correlational studies that preclude causal inferences. In order to determine whether changes in behavioural intention engender behaviour change, participants should be assigned randomly to a treatment that significantly increases the strength of respective intentions relative to a control condition, and differences in subsequent behaviour should be compared. The present research obtained 47 experimental tests of intention-behaviour relations that satisfied these criteria. Meta-analysis showed that a medium-to-large change in intention (d = 0.66) leads to a small-to-medium change in behaviour (d = 0.36). The review also identified several conceptual factors, methodological features, and intervention characteristics that moderate intention-behaviour consistency. (Author/publisher)
Abstract