Biologic clock of aging (123RF)

“Wait a minute”,” just a minute”, “one minute please”, “can you spare a minute?” We use these phrases on a daily basis, but what do we mean when we say them? Many a time we go bananas on somebody who promises to come back in a minute only to show up 10 minutes later with an innocent look, a shrug and an off-hand comment: “What’s the fuss, I was away less than a minute?” Surely we don’t mean the literal 60- second time unit, or we’d all be chronically late. Rather, I think we are intending to say something to the effect of “a very brief length time, almost immediately.” Which begs the question: is there a subjective time perception that is different from objective time? And if so, what is the unit of subjective time? In other words, we can define an objective time unit, say 1 minute or 1 second. But what would be the subjective unit?

If I didn’t lose you with this arcane philosophical musing, you are going to be rewarded with some neat insights.


But first, here are a few questions:

  • What’s the average time that we wave good bye?
  • What’s the average time for a bout of baby vocalization (babbling) and hand gestures?
  • What about adult speech? How long is the average phrase?
  • How long does a quiet breath take, on average?
  • How long is the average musical phrase? ( hum to yourself the opening phrases of Beethoven’s Fifth Symphony (tatata taaa,…).
  • How long does it take a giraffe to defecate? (Sorry, no jokes! we are being scientific here). Or for that matter, a variety of other animal functions, like chewing? Have you ever noticed the rhythm of a dog lapping water?
  • Do you know how long it takes the vagus nerve to activate the heart and lungs in anticipation of a race, or a fight?

The answer, my friend, is written in the brain. And, the answer is about 3 seconds!


How was this determined?

As far back as 1911 it was reported by Wundt that if you subject somebody to a series of stimuli, the average time for a stimulus to be perceived as unique is about 2.5 seconds. If you separate the next stimulus by more than 3 seconds, it will be perceived as separate. Even spoken language is constructed in 3 second windows. When people are asked to recite poetry they speak in rhythms of 3 seconds, regardless of their native language. Studies have also suggested that the temporal window for motor units is also 3 seconds long. An analysis of 1542 hand and body movements of 3 different cultures (Yanomami, Himba and Trociander) revealed that 93% lasted about 2-3 seconds. And there are numerous other studies of human and animal activity coming to the same conclusion: the unit of biological activity, be it motor (hand and body movements), cognitive (speech) or psychological (perception) is about 2-3 seconds.


More evidence

If you noticed, all those activities involved one individual. What about an activity that involves more than one? In other words, what about social interactions? I have seen lions copulate in the wild, in Botswana. Guess how long it took the male to finish and fall exhausted alongside his lioness lover? Hint: it lasted long enough to give 1-2 grunts. Even more interestingly, he recovered his strength a few minutes later and repeated the 3-second act again, and again, and again…for up to four days!

Developmental psychologist Emese Nagy of Dundee University in the U.K. set out to investigate a human social activity. She had a rich trove of data: The televised Beijing Olympics, recording the hugs between athletes following an event. Nagy conducted a frame-by-frame analysis of video recordings of the Olympic finals in 21 sports, among them badminton, wrestling, and swimming. She had an independent observer time 188 hugs between athletes from 32 nations and their coaches, teammates, and rivals.

Regardless of the athletes’ and their partners’ gender or national origin, the hugs lasted about 3 seconds on average, Nagy reports this month in the Journal of Ethology. Not surprisingly, the identity of the partner mattered: athletes hugged their coaches somewhat longer than they did their teammates and hugged their opponents the shortest amount of time. But the average still came out to be 3 seconds.


What’s the biological basis for this fascinating phenomenon?

It’s in the way our brain functions. It takes 2-3 seconds for the brain’s attentional mechanisms to disengage from one stimulus and engage in another. This is the basis of ours, and other animals’ perception of the world around us in 2 to 3-second time frames. I find this story fascinating, in spite of the 3-second time frames, I wrote about it.

Dov Michaeli, MD, PhD
Dov Michaeli, MD, PhD loves to write about the brain and human behavior as well as translate complicated basic science concepts into entertainment for the rest of us. He was a professor at the University of California San Francisco before leaving to enter the world of biotech. He served as the Chief Medical Officer of biotech companies, including Aphton Corporation. He also founded and served as the CEO of Madah Medica, an early stage biotech company developing products to improve post-surgical pain control. He is now retired and enjoys working out, following the stock market, travelling the world, and, of course, writing for TDWI.


  1. This is neat. Turns out that our entire species and some others (i.e., that hopeless romantic, the male lion) have ADHD. I am kidding, of course, but I find the cross-cultural fondness for 3-second acts heartening. We are treated to a variety of finger-wags about the modern U.S. being especially compressed and disjointed in our habits. Maybe it is not just us, and maybe the so-called “curse of modernism” is not a curse at all?

Comments are closed.