Why Life Seems to Speed Up as We Age

I remember when I was a kid waiting an hour for my favorite TV show to come on, which was Sharon, Lois & Bram. That felt like eternity, but as I've gotten older, everything seems to have sped up. Time is going much faster. That's something virtually everyone agrees upon.

"Yeah, I feel like- I feel like it does." "Oh man, so much." "Each year sort of gets faster and faster." But why is this? Is it just an illusion or are there good scientific reasons why time appears to go faster as we get older? Well, I'm working with the National Geographic Channel's Brain Games, a show that explores the inner workings of the human mind through experiments and interactive games to test out some theories about why this actually occurs.

There is a reasonable sounding argument that says each year goes faster because it makes up a smaller fraction of your entire life. "Let's say I was only 20. One year is only 1/20th of my age. But when I'm 67, one year is 1/67th of my age." This graph shows one year as a percentage of your life at each age. But what I find weird about this is if you add up the area underneath the curve, you'll find that you've already lived half of the total by age 6. So, I really don't think this is how our brains perceive time. You really think that, like, a day now is- "Of course not." [laughter]

I think there are better reasons why time appears to speed up as we get older. So I've come to Venice Beach to find two groups of people: the older and younger to see if their perceptions of time differ. So what I want to do is I want to set my timer going and without counting, you tell me when you think a minute is up. "Let's go." Start. "Okay."

Everywhere around the world, when this experiment is performed, older people typically overestimate while younger people measure it quite accurately. "Alright, probably stop?" "Yep." Wooo, one minute, two seconds. A minute and two seconds. A minute and five. As we get older, the rate at which our neurons fire, or our neuron conduction velocity, it decreases. And you can think of this firing rate a little bit like an internal clock. And so, if our internal clock is slowing down, that would make everything else, external time, seem to be speeding up.

"I'm going to tell you the time." Now? "Now." "One minute." That's it? That was one minute? "One minute." Minute, seventeen seconds. "Not bad, right?" Not bad. "I thought I'd be a lot closer actually, but I guess I wasn't." Do you want to know what it really was? One minute forty seven. "No way, it was almost two minutes? It was actually almost two minutes."

"It really is amazing how fast time flies by, it really is." Our sense of time, or chronoception, is not like one of the standard five senses. It has no specialized receptor cells and it does not appear to be localized in just one part of the brain. Perhaps this suggests that it's not one coherent thing at all. But it does seem that our perception of time is very fundamental.

Studies of rats have shown that even with their neocortex removed - that is, the higher order thinking part of their brains- they are still able to learn how to time forty seconds accurately. That's quite remarkable, and it suggests our sense of time evolved early and is one of the fundamental functions of the brain. But that doesn't mean our brains always represent time faithfully.

For example, have you noticed that really good movies seem to go by much faster than they actually are? Or do you notice that your vacations fly by? There are good reasons for this. When we're focused on something, we don't notice that time is passing and that makes them feel in the moment shorter than they actually are. At its best, this results in a mental state called "flow". This can happen when playing sports or video games or artists when they're fully engrossed in their work or people meditating.

So I would argue another reason time speeds up as we age is because we are more often engrossed in what we're doing. Another thing that appears to make time speed up is repetition. I'm going to show you a series of images and I want you to consider how long each one appears on the screen. Are you ready? Go. So which one appeared to last the longest? If you're like most people, you'd probably say the dog. But all of those images actually appeared on screen for the same length of time.

The dog seemed longer because it was novel and therefore, your brain had to invest more energy in processing it. What's remarkable is that our sense of how long something is - or subjective duration- it correlates highly with how much energy we're using in our brains. Now, if you study how much energy people use in their brains over the course of their lifetime, you'll find that it peaks around age five. If you think about it, this kind of makes sense because when you're a kid, almost everything is novel to you.

And therefore, your brain needs to use more energy, fully 66% of your resting energy intake. That's used by the brain because of all the novel experiences and that must, at least in part, explain why time appears to go more slowly. So, what can we do to slow time down? Well, studies have shown that being afraid increases our perception of time. When arachnophobes were forced to stare at spiders for 45 seconds - yes, this is a real experiment - those arachnophobes judged that experience as lasting much longer than 45 seconds, as you would kind of expect.

Plus, experiments involving skydivers or people falling showed that they judged their experience to last much longer than it actually is. Another time when time appears to pass slowly is when you're bored. "You know, when you're waiting and waiting, that's all you think about, so it seems like time drags forever." Since there is so little to focus on, you are acutely aware of just how much time is passing, and so these boring moments drag on and on.

So, if you really want to slow down your experience of time, you could scare yourself, take up extreme sports, get into accidents and intersperse all of that with periods of boredom. But this viewpoint ignores one important fact, which is that we don't experience time as just one thing. We think about time as it passes, but also as it has passed before, when we remember it. And those two ways of looking at time, they don't align.

So for example, holidays, they feel like they go by really fast, but when you think back upon them, they last a long time. That's because you had a lot of novel experiences and your brain formed a lot of memories. And it judges the duration of that vacation by the number of memories that were formed. All that novelty means lots of memories means it feels like it took a long time, but in the moment, it felt fast.

This is the paradox, the great paradox, of our perception of time. If you want time to go slowly, there are a lot of things you can expose yourself to that will slow time down, but they won't necessarily be pleasant. So maybe the happiest life and the longest remembered life is one where time really seems to fly.

It's like Einstein said, "Put your hand on a stove for a minute and it'll feel like an hour. But sit next to a pretty girl for an hour and it'll feel like a minute." So, what would you like your life to feel like? I want to thank the National Geographic Channel for sponsoring this episode of Veritasium. And if you want to introduce more novelty into your life, than you should check out their series, "Brain Games".

The new season begins February 14th at 9/8 Central. And this season, they have an episode about all of your senses, including your sense of time, chronoception. So if you want to find out more, than check out the link to their website in the description. And thank you for watching. Did that feel like that lasted long?