in a 2014 u.s. study surveying procrastination and impulsiveness in fraternal- and identical twin pairs, both traits were found to be "moderately heritable". the two traits were not separable at the genetic level (r = 1.0), meaning no unique genetic influences of either trait alone was found. the authors confirmed three constructs developed from the evolutionary hypothesis that procrastination arose as a by-product of impulsivity: "(a) procrastination is heritable, (b) the two traits share considerable genetic variation, and (c) goal-management ability is an important component of this shared variation."