Q: What is the science behind TED's 18-minute rule?

A: The 18-minute rule for TED talks is based on the limits of the human brain's ability to retain information and stay engaged. Neuroscientists have found that the average attention span of an adult is between 10 and 20 minutes. Beyond that, it becomes increasingly difficult to maintain focus and retain information. Additionally, the brain is capable of processing a limited amount of new information at a time, and 18 minutes represents an ideal window for conveying a meaningful idea or story without overwhelming the audience. So, the 18-minute time limit for TED talks is designed to accommodate the brain's limits and promote concise, focused talks that are more effective and memorable. (source: TED website and various sources from online search results)