What concept suggests that there is an optimal period for second language acquisition?

The concept that indicates there is an optimal period for second language acquisition is known as the Critical Period Hypothesis. This hypothesis suggests that there is a specific timeframe in which individuals can learn a second language more easily and effectively, typically during early childhood. The idea is that during this period, the brain's plasticity allows for more intuitive understanding and production of language.

Research has shown that children are generally able to pick up languages with native-like proficiency when exposed to them at a young age. As individuals grow older, their ability to acquire a new language diminishes, and they may struggle with aspects such as pronunciation or grammatical structures that younger learners can adopt naturally.

In contrast, cultural universals pertain to the shared features or characteristics across different cultures, transculture refers to the interaction between different cultures leading to the emergence of new cultural forms, and assimilation describes the process where individuals or groups adopt the traits of another culture, often losing their original cultural identity in the process. These concepts do not address the timing or effectiveness of second language acquisition in the same way the Critical Period Hypothesis does.