Everyone understands the benefits of thumbs for the human race. Not too many people count faster interactions as one of those benefits. Yet thumbs are so much more than their mechanical uses would suggest. In the United States, western Europe, and several other regions, for example, the simple act of a thumbs-up is widely and instantly recognized as a signal of support and alignment. (This is not the case everywhere in the world. Quite the contrary: In certain countries and regions, such as Greece, the Middle East, and others, the thumbs-up sign is an obscene gesture and a serious insult. When doing business in areas with which you are unfamiliar—and in cross-cultural teams—check the practices of the cultures involved before you use gestures.)