Early humans likely reached a positive feedback loop of cultural and technological development, often referred to as the "cultural explosion" or "cultural revolution," around 50,000 to 70,000 years ago. This period marked a significant acceleration in human progress, including the development of complex tools, art, symbolic communication, and more advanced social structures. It was a time when humans began to exhibit a capacity for innovation and cultural transmission that set them apart from earlier hominid species. This positive feedback loop of cultural and technological growth eventually led to the diverse range of societies and civilizations we see today.