[vidarh]

The Spanish and English dual meaning both comes from latin, so the similarity in other languages with influence from latin does not provide any evidence in support of this idea developing independently (nor does it provide evidence against it).

Looking up the Chinese etymology seems to imply both the Latin and Chinese probably came to have the dual use for the same reason (agriculture leading to equating labour with resulting in fruit/produce), without any obvious direct connection.

Who knows... It does seem a quite logical step for new agricultural societies to make that connection.

[icelancer]

Large crop yields = good thing. Seems like a reasonable connection.