Here's why:
* Limited historical records: Our knowledge of ancient cultures is often incomplete, and the evidence of writing systems may have been lost to time.
* Oral traditions: Many cultures relied heavily on oral traditions for knowledge, history, and cultural transmission. These traditions were often complex and intricate, and their absence doesn't necessarily mean a lack of a sophisticated cultural system.
* Ongoing research: Archaeological discoveries and linguistic studies are constantly uncovering new information about ancient cultures, including the presence of written systems previously unknown.
However, some cultures are believed to have lacked written languages until relatively recently, such as:
* Many indigenous tribes in the Americas: While some Mesoamerican civilizations (like the Maya) had complex writing systems, many tribes across North and South America relied primarily on oral traditions.
* Some Australian Aboriginal groups: While some groups have developed their own writing systems in recent times, many traditionally relied on complex oral languages and symbolic systems.
* Certain tribes in Africa and Oceania: Similarly, many indigenous groups in these regions have maintained strong oral traditions and have only adopted written languages more recently.
Important Note: This is not an exhaustive list, and it is crucial to remember that cultures evolve over time. Many groups may have adopted writing systems in the last few centuries, even if they previously relied on oral traditions.
It's also crucial to avoid generalizations. Within any cultural group, there may be subgroups or individuals who developed unique forms of writing or communication.