The author has always shown interest in bilinguals who are also bicultural – also known as bicultural bilinguals. In this chapter, he concentrates on the bicultural component of these bilinguals: they take part, to varying degrees, in the life of two or more cultures; they adapt, at least in part, their attitudes, behaviors, values, languages, and so on to these cultures; and they combine and blend aspects of the cultures involved. He then evokes how one becomes bicultural and how biculturalism evolves over time. This is followed by his proposal to adapt the language mode concept to account for how biculturals modify their behaviors in different situations. Biculturals find themselves at various points along a situational continuum – cultural this time – that requires different types of behavior and attitudes depending on the situation. At one end they are in a monocultural mode, and at the other end they are in a bicultural mode. The last two sections concern bicultural identity and the question of whether bicultural bilinguals change personality when they change language.