EIQ version used - Minor correction 21 March 2008 Dan T.A. Eisenberg, Northwestern University An astute reader pointed out a minor point of confusion in the manuscript. The Eysenck Impulsivity measure (EIQ) used in this manuscript is that of the 1978 citation:Eysenck SBG, Eysenck HJ: Impulsiveness and Venturesomeness - Their Position in a Dimensional System of Personality Description. Psychol Rep 1978, 43(3):1247-1255. We did not use the specific EIQ measure in the other citation: Eysenck SBG, Pearson PR, Easting G, Allsopp JF: Age Norms for Impulsiveness, Venturesomeness and Empathy in Adults. Pers Individ Dif 1985, 6(5):613-619. Hope that clears up any confusion.Dan Eisenberg Competing interests I have no competing interests to declare.