The thumb tribe (or sometimes thumb generation^[1]) is the younger generation with members who are more adept at texting using their thumbs than talking on the phone.^[2][3][4] In 2002, a trend was identified among young people who used mobile phones for many activities, such as texting, email, entertainment, and conversations, as opposed to using keyboards with traditional desktop computers.^[5] This marked a shift in the favorite digit such that activities typically done by the forefinger, such as pointing at things or ringing doorbells, were now being done with the thumb.^[6] The term thumb tribe has been used by marketers to identify younger consumers^[5] and in politics to identify persons who are not part of the younger generation, such as American politician Mitt Romney, who in 2010 was said to have owned a mobile phone but not been able to use it dexterously.^[7][8] Researchers reported in 2002 that this had led to the thumb being physically stronger and more flexible for many young people.^[9] There are medical implications as well; excessive use of thumbs can lead to muscle pain and possible occupational problems.

The term thumb tribe was first used in Japan to identify the "younger generation of Japanese texters".^[10] Japanese youth used their keitai or mobile phone to download music, access Japan's version of Myspace called mixi, surf the web, check train timetables and so forth.^[11] This group is identified as a common source of smart mobs that assemble seemingly spontaneously.^[12] The Japanese texting style relies heavily on the thumb, according to a report in NBC News.^[13]

They've grown up in a world that is dynamically different from the one we lived in. What kind of cars do they want? And what gadgets? They don't even use computers - computers now perceived as going the way of B&W television. At what point do their childhood toys and t'ween technology devices merge? And what future outcomes do they, and marketer-manufacturers expect?

— H. Martin Calle, 2007^[5]