We recorded the direction of hair whorl rotation in samples of male right- and non-right-handers. The data corroborate those of Klar (2003) in showing equal numbers of clockwise and anti-clockwise whorls in non-right-handers but an excess of clockwise whorls in right-handers. The findings support the view that in some proportion of the population direction of coiling arises as a consequence of random events occurring during early (pre-natal) development of the nervous system, while in the remainder of the population there is a systematic bias towards a clockwise direction of rotation. The association with handedness implies that the latter is in a very large measure biologically rather than culturally determined.