There are contrasting transfer patterns for thumbs and big toes on the one hand and the remaining digits on the other: Whereas the former are likely to be built on kin-terms of an older, ascending generation (e.g. ‘mother of the hand/foot’), the remaining fingers and toes tend to be derived from expressions involving terms for offspring or other younger relatives (e.g. ‘child of the hand/foot’)
Standardized
When terms for thumbs, big toes and remaining digits are derived from kin-terms, thumbs and big toes are likely to be built on kin-terms of an older, ascending generation and the remaining fingers and toes tend to be derived from terms for offspring or other younger relatives.