Here's why:
* Simultaneous acquisition: They learned both languages from a very young age, at the same time, without a dominant language.
* Equal proficiency: They likely developed similar levels of fluency and proficiency in both languages.
* Native-like abilities: They typically exhibit native-like abilities in both languages, with natural pronunciation, grammar, and vocabulary.
Other types of bilingualism include:
* Sequential bilingual: Learning a second language after acquiring the first language.
* Compound bilingual: Acquiring two languages together in a single context (e.g., a child raised in a bilingual household).
* Coordinate bilingual: Learning two languages separately, often in different contexts (e.g., school and home).
However, it's important to remember that bilingualism is a spectrum, and there are many nuances. A person may be considered "balanced" even if they have slightly more fluency in one language than the other. Ultimately, the specific type of bilingualism depends on the individual's language learning experiences and proficiency levels.