It’s common to differentiate between ‘first generation’ immigrants (i.e. people who moved to live in a different country), and ‘second generation’ immigrants (i.e. their descendants). It might look like a systematic (hence scientific?) approach, but it’s not appropriate. Typically, we use the term generation like this: “The bakery is owned and operated by fifth-generation baker Sylvain Chaillout and his parents.” Here we have baker after baker, and supposedly this makes Sylvain Chaillout (the firth-generation baker) more of a baker than any Johnny-come-lately baker. Contrast this with the ‘second generation’ immigrant, a person who is by most people’s definition not an immigrant him or herself, and if anything less of an immigrant than any Johnny-come-lately immigrant who has just arrived.
Image: cc-by-nc-nc open-arms