Subject:  Attention – TED Talk Time Limit

Event:  TED Founded, 1984

In 2005, Time magazine reported that research conducted by Microsoft Corporation concluded that the attention span of the average individual dropped from 12 seconds in 2000 to 8 seconds in 2005. Time also noted that the attention span of a goldfish is 9 seconds (1).

Bill Gates at TED 2009 (3259638679).jpg
Bill Gates at TED 2009 (Wikimedia Commons)

A bit more optimistic view of the human attention span can be found at TED conferences, where the rule is no presentation may exceed 18-minutes.  It’s hard to argue with the success of TED Talks; they are streamed more than 2 million times per day.

TED (Technology, Entertainment, and Design) was created by Richard Saul Wurman, who hosted the first TED conference in Monterey, California, on this day, Thursday, February 23, 1984.  Attendees paid $475 to watch a variety of 18-minute presentations.  In 2009, TED began to depart from its once-a-year model by granting licenses to third parties for community-level TEDx events.  The website was launched in 2006, and today there are TED events in more than 130 countries.

As TED curator Chris Anderson explains, the time limit is no accident; instead, it is a purposeful standard that helps both the speaker communicate clearly and the audience learn more efficiently:

It is long enough to be serious and short enough to hold people’s attention. It turns out that this length also works incredibly well online. It’s the length of a coffee break. So, you watch a great talk, and forward the link to two or three people. It can go viral, very easily. The 18-minute length also works much like the way Twitter forces people to be disciplined in what they write. By forcing speakers who are used to going on for 45 minutes to bring it down to 18, you get them to really think about what they want to say. What is the key point they want to communicate? It has a clarifying effect. It brings discipline. 

Communication coach Carmine Gallo explains the logic of the 18-minute time rule based on the physiology of the brain:

The 18-minute rule also works because the brain is an energy hog. The average adult human brain only weighs about three pounds, but it consumes an inordinate amount of glucose, oxygen, and blood flow. As the brain takes in new information and is forced to process it, millions of neurons are firing at once, burning energy and leading to fatigue and exhaustion. (2)

Recall, Retrieve, Recite, Ruminate, Reflect, Reason:  What is the rationale behind the 18-minute time limit for TED Talks?

Challenge – Under 18 But Not Minor:  Some of the most effective and memorable speeches in history come in under the 18-minute rule.  For example, Martin Luther King’s “I Have a Dream” speech, which he gave at the March on Washington on August 28, 1963, was 17 minutes long.  Speaking at a normal pace, the average 18-minute speech would be approximately 2,500 words.  Do some research on great speeches, and find one that you like that is under 2,500 words.  Explain the rhetorical context of the speech and, besides the fact that it is less than 18-minutes long, explain why you feel it is effective.


1-McSpadden, Kevin. “You Now Have a Shorter Attention Span Than a Goldfish” 14 May 2015.  

2-Gallo, Carmine. “The Science Behind TED’s 18-Minute Rule.” 13 March 2014.