thumbs up

A thumb signal, usually described as a thumbs-up or thumbs-down, is a common hand gesture achieved by a closed fist held with the thumb extended upward or downward, respectively. The thumbs-up gesture is associated with positivity, approval, achievement, satisfaction and solidarity, while the thumbs-down gesture is associated with concern, disapproval, dissatisfaction, rejection and failure. History Natural human behaviour While the exact source of the thumb gesture is obscure, several origins have been proposed. Carleton S. Coon, having observed Barbary apes in Gibraltar using the gesture, hypothesised in the anthropological classic The Story of Man that it is a mutual celebration of having opposable thumbs. Critics have suggested, however, that the apes may be simply imitating humans. Ancient Rome