Right‐handed fossil humans

Abstract

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right- to 1 left-hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right-handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right-handed fossils come from Europe, but a single maxilla from a Homo habilis, OH-65, shows a predominance of right oblique scratches, thus extending right-handedness into the early Pleistocene of Africa. Other studies show right-handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non-European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right-handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens.

Hand preferences in coordinated bimanual tasks in non-human primates: a systematic review and meta-analysis

“…In contrast, with humans, around 90% of the population are right-handed (Annett, 2006;Papadatou-Pastou et al, 2020). The presence of population-level right-side bias has also been identified in the fossil record for some hominin species such as Homo neanderthalensis (Lozano et al, 2017;Uomini, 2011) or Homo habilis (Frayer et al, 2016). In addition, great apes have displayed population-level handedness for some tasks (e.g.…”

Bilaterally Symmetrical: To Be or Not to Be?

“…We are nearly all right-handed, an asymmetry woven into many cultural practices [11] and often a source of prejudice against the 12 percent or so of left-handers. Fossil evidence suggests that even the Neanderthals were right-handed, perhaps in the same proportion as in humans [12]. Historically, this ubiquitous asymmetry seems to have been regarded as behavioral, or habitual, rather than biological.…”

Right or left? Determining the hand holding the tool from use traces

“…Bermúdez de Castro et al, 2003, 1988Condemi et al, 2017;Estalrrich and Rosas, 2013;Fiore et al, 2015;Frayer et al, 2012Frayer et al, , 2010Lozano et al, 2009;Poza-Rey et al, 2017;Xing et al, 2017). This could be the case as early as 1.8 Ma as suggested by the study of labial striations on the OH-65 fossil's anterior teeth (Lozano et al, 2017).…”