It will soon be time for the annual ritual of New Year’s resolutions, which we invariably fail to follow and put off again until next year. It would appear that the blame lies with our prehistoric ancestors. A twin study from the United States has found that procrastination (pro: in favour of, crastinus: tomorrow) is an inherited trait which is strongly linked to impulsivity. Data were gathered from the Colorado Longitudinal Twin Study. There were 663 participants, from both identical and same-sex fraternal twin pairs.