The thumb is the first digit of the hand. When a person is standing in the medical anatomical position (where the palm is facing anteriorly), the thumb is the lateral-most digit. The Medical Latin English noun for thumb is pollex (compare hallux for big toe), and the corresponding adjective for thumb is pollical.

The English word "finger" has two senses, even in the context of appendages of a single typical human hand:

Linguistically, it appears that the original sense was the broader of these two: penkwe-ros (also rendered as penqrós) was, in the inferred Proto-Indo-European language, a suffixed form of penkwe (or penqe), which has given rise to many Indo-European-family words (tens of them defined in English dictionaries) that involve or flow from concepts of fiveness.

The thumb shares the following with each of the other four fingers:

The thumb contrasts with each of the other four by being the only digit that:

and hence the etymology of the word: "tum" is Proto-Indo-European for " swelling " (cf "tumour" and "thigh") since the thumb is the stoutest of the digits.

Jane McGonigal (born 1977) is a game designer, game researcher, and author, specializing in pervasive gaming and alternate reality games (ARGs).

McGonigal writes and speaks about alternate reality games and massively multiplayer online gaming, especially about the way that collective intelligence can be generated and utilized as a means for improving the quality of human life or working towards the solution of social ills. She has stated that gaming should be moving "towards Nobel Prizes." McGonigal has been called "the current public face of gamification".

She has taught game design and game theory at the San Francisco Art Institute and the University of California, Berkeley and she currently serves as the Director of Game Research & Development at Institute for the Future. In 2006, she was named to the MIT Technology Review TR35 as one of the top 35 innovators in the world under the age of 35.

Additionally, she has collaborated on commissioned games for the Whitney Museum of American Art and the Museum of Contemporary Art, Los Angeles.^{[citation needed]}