We propose a model of impulsivity that predicts both domain–general and domain–specific variance in behaviours that produce short–term gratification at the expense of long–term goals and standards. Specifically, we posit that domain–general impulsivity is explained by domain–general self–control strategies and resources, whereas domain–specific impulsivity is explained by how tempting individuals find various impulsive behaviours, and to a lesser extent, in perceptions of their long–term harm. Using a novel self–report measure, factor analyses produced six (non–exhaustive) domains of impulsive behaviour (Studies 1–2): work, interpersonal relationships, drugs, food, exercise and finances. Domain–general self–control explained 40% of the variance in domain–general impulsive behaviour between individuals, r effect = .71. Domain–specific temptation ( r effect = .83) and perceived harm ( r effect = −.26) explained 40% and 2% of the unique within–individual variance in impulsive behaviour, respectively (59% together). In Study 3, we recruited individuals in special interest groups (e.g. procrastinators) to confirm that individuals who are especially tempted by behaviours in their target domain are not likely to be more tempted in non–target domains. Copyright © 2011 John Wiley & Sons, Ltd.