Abstract
The Sichuan snub-nosed monkey (Rhinopithecus roxellana) is a typical arboreal group-living Old-World primate and has been studied broadly in hand preference. However, infants have not been tested independently from other immature individuals to date. The purpose of the present study was to investigate hand preference in a spontaneously unimanual feeding task in nine infants at 12 months and the relationship of hand preference with their parents in R. roxellanae. Most infants (89%) showed individual-level hand preference. No correlation was found in the direction of hand preference between infant and its parents, and a significant negative correlation in the strength of hand preference was found between infants and their mothers (r = −0.715, p = 0.03). Moreover, there was no sex difference in the direction and strength of hand preference both in infants and adults (i.e., parents). Meanwhile, the strength of hand preference in adults was stronger than that in infants. This study is a first and preliminary exploration for the expression of hand preference in R. roxellanae infants and whether their hand preference was influenced by familial inheritance.
Highlights
Handedness was considered as the most obvious index and an exclusive characteristic in human brain asymmetry and has been greatly studied [1,2]
InResults total, 329 data points were recorded in 9 R. roxellana infants
About the previous studies on R. roxellana, no sex effect was found either in the unimanual task [29,30,31] or in the bimanual coordinated task [33], which was supported by the current study. This is the first investigation on the expression of hand preference in 12-month-old R. roxellana infants and the relationship with their parents
Summary
Handedness was considered as the most obvious index and an exclusive characteristic in human brain asymmetry and has been greatly studied [1,2]. Almost 90% of humans showed right-hand preference at a population level [3]. The evolution and origin of human right-handedness remain unsolved [4,5]. Previous studies showed that hand preference was present at birth and appears gradually during development in humans. No more than 6-month-old infants begin to present strong hand preference, become stronger at 6 months of life and are tending towards stability over these ages [6,7,8,9]. More recently one review summarized that no one study can completely excluded genetic or environmental influence on the formation of hand preference [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
