thumb tribe; thumb generation
Coined term for people who constantly type on their phones with their thumbs, especially for texting or social media. Often used in media and social commentary.
It's said that all young people these days are part of the thumb tribe.
The train was full of people typing away on their phones.
pachinko addict
Slang extension: a person addicted to pachinko, from the repetitive thumb motion used to operate the machine. Less common than the phone-typing sense.
He's a pachinko addict and goes to the parlor every day.