Why Does Time Seem to Pass at Different Speeds?
Does time really speed up as we get older?
Posted Jul 03, 2011
I'm six years old, in the car with my parents and brother, travelling back from our annual two week holiday in Conwy, North Wales. It's dark and the journey seems to take forever. I lie in the back seat, watching the orange streetlights and the houses pass by, wondering if we're ever going to get home.
"Are we nearly there yet?" I ask my father.
"Don't be silly," he says. "We only set off half an hour ago."
My mum plays a few games with us to make the time pass faster. We listen to the radio for a while. Then I fall asleep. When I wake up it seems like I've been in the car for an eternity and I can't believe we're still not home.
The journey from Conwy to Manchester took two hours when I was a child and still takes roughly two hours now (although slightly less due to improvements in roads). I made the journey again a few years ago and couldn't believe how short it seemed now, from my adult perspective. Those two hours — which seemed like an eternity when I was 6 — were nothing. My girlfriend was driving, and we chatted, listened to tapes, watched the Welsh countryside give way to the urban sprawl of north-west England, and we were back in Manchester almost before we knew it. It was a little frightening — what had happened to all the time that two hours contained when I was six years old?
This story appears to fit with most people's experience. Most of us feel that time moved very slowly when we were children and is gradually speeding up as we grow older. We've all remarked on it: how Christmas seems to come around quicker every year, how you're just getting used to writing the date of the new year on your cheques and you realise that it's almost over, how your children are about to finish school when it doesn't seem long since you were changing their nappies.
Questionnaires by psychologists have shown that almost everyone — including college students — feels that time is passing faster now compared to when they were half or a quarter as old. And perhaps most strikingly, a number of experiments have shown that, when older people are asked to guess how long intervals of time are, or to ‘reproduce' the length of periods of time, they guess a shorter amount than younger people.
We usually become conscious of this speeding up around our late twenties, when many of us have settled down. We have steady jobs, marriages, and homes, and our lives become ordered into routines — the daily routine of working, coming home, having dinner and watching TV; the weekly routine of perhaps going to the gym on Monday night, going to the cinema on Wednesday night, and going for a drink with friends on Friday night; and the yearly routine of birthdays, bank holidays and two weeks' holiday in the summer. After a few years, we start to realise that the time it takes us to run through these routines seems to be decreasing, as if we're on a turntable picking up speed with every rotation.
This speeding up is probably responsible for the phenomenon which psychologists call forward telescoping: our tendency to think that past events have happened more recently than they actually have. Marriages, deaths, births of a child — when we look back at these and other significant events, we're often surprised that they happened so long ago, shocked to find that it's already been four years since a friend died when we thought it was only a couple of years, or that a niece or nephew is already ten years old when it only seems like three or four years since they were born.
The Proportional and Biological Theories
So why do we experience this speeding up of time?
One popular answer is the proportional theory, which suggests that the important factor is that, as you get older, each time period constitutes a smaller fraction of your life as a whole.
This theory seems to have been put forward in 1877 by Paul Janet, who suggested the law that, as William James describes it, "the apparent length of an interval at a given epoch of a man's life is proportional to the total length of the life itself. A child of 10 feels a year as 1/10 of his whole life — a man of 50 as 1/50, the whole life meanwhile apparently preserving a constant length."
At the age of one month, a week is a quarter of your whole life, so it's inevitable that it seems to last forever. At the age of 14, one year constitutes around 7% of your life, which seems to be a large amount of time too. But at the age of 30, a week is only a tiny percentage of your life, and at 50 a year is only 2% of your life, so your subjective sense is that these are insignificant periods of time which pass very quickly.
There is some sense to this theory — it does offer an explanation for why the speed of time seems to increase gradually and evenly, with almost mathematical consistency. One problem with it, however, is that it tries to explain present time purely in terms of past time. The assumption is that we continually experience our lives as a whole, and perceive each day, week, month or year becoming more insignificant in relation to the whole. But we don't live our lives like this. We live in terms of much smaller periods of time, from hour to hour and day to day, dealing with each time period on its own merits, independently of all that has gone before.
There are also biological theories. One is that the speeding up of time is linked to how our metabolism gradually slows down as we grow older. Because children's hearts beat faster than ours, because they breathe more quickly and their blood flows more quickly, their body clocks "cover" more time within the space of 24 hours than ours do as adults.
Children live through more time simply because they're moving through time faster. Think of a clock which is set to run 25% faster than normal time: After 12 hours of normal time it has covered 15 hours, and after 24 hours of normal time it has covered 30 hours, which means that, from that clock's point of view, a day has contained more time than usual. On the other hand, older people are like clocks that run slower than normal, so that they lag behind, and cover less than 24 hours against a normal clock.
Also from a biological perspective, there is the body temperature theory. In the 1930s, the psychologist Hudson Hoagland conducted a series of experiments which showed that body temperature causes different perceptions of time. Once, when his wife was ill with the flu and he was looking after her, he noticed that she complained that he'd been away for a long time even if he was only away for a few moments. With admirable scientific detachment, Hoagland tested her perception of time at different temperatures and found that the higher her temperature, the more time seemed to slow down for her, and the longer she experienced each time period.
Hoagland followed this up with several semi-sadistic experiments with students, which involved them enduring temperatures of up to 65C and wearing heated helmets. These showed that raising a person's body temperature can slow down their sense of time passing by up to 20%. And the important point here may be that children have a higher body temperature than adults, which may mean that time is "expanded" for them. And in a similar way, our body temperature gradually lowers.
The Perceptual Theory of Time
In my view, the best way of explaining the speeding up of time is through what I call the perceptual theory. This is the explanation I present in my book Making Time. In my view, the speeding up of time we experience is mainly related to our perception of the world around us and of our experiences, and how this perception changes as we grow older.
The speed of time seems to be largely determined by how much information our minds absorb and process — the more information there is, the slower time goes. This connection was verified by the psychologist Robert Ornstein in the 1960s. In a series of experiments, Ornstein played tapes to volunteers with various kinds of sound information on them, such as simple clicking sounds and household noises. At the end, he asked them to estimate how long they had listened to the tape. He found that when there was more information on the tape, such as double the number of clicking noises, the volunteers estimated the time period to be longer.
He found that this applied to the complexity of the information too. When they were asked to examine different drawings and paintings, the participants with the most complex images estimated the time period to be longest.
And if more information slows down time, perhaps part of the reason why time goes so slowly for children is because of the massive amount of perceptual information that they take in from the world around them. Young children appear to live in a completely different world to adults — a much more intense, real, fascinating, and beautiful one. This is one of the reasons why we often recall childhood as a time of bliss — because the world was a much more exciting and beautiful place to us then, and all our experiences were so intense.
Children's heightened perception means that they're constantly taking in all kinds of details which pass adults by — tiny cracks in windows, insects crawling across the floor, patterns of sunlight on the carpet. And even the larger scale things which we can see seem to be more real to them, to be brighter, with more presence and is-ness. All of this information stretches out time for children.
However, as we get older, we lose this intensity of perception, and the world becomes a dreary and familiar place — so dreary and familiar that we stop paying attention to it. After all, why should you pay attention to the buildings or streets you pass on the way to work? You've seen these things thousands of times before, and they're not beautiful or fascinating, they're just... ordinary. As Wordsworth puts it in his famous poem "Intimations of Immortality," the childhood vision which enabled to all things "apparelled in celestial light," begins to "fade into the light of common day." And this is why time speeds up for us. As we become adults, we begin to switch off the wonder and is-ness of the world. We gradually stop paying conscious attention to our surroundings and experience. As a result, we take in less information, which means that time passes more quickly. Time is less "stretched" with information.
Old and New Experience
And once we become adults, there is a process of progressive familiarisation which continues throughout our lives. The longer we're alive, the more familiar the world becomes, so that the amount of perceptual information we absorb decreases with every year, and time seems to pass faster every year.
There are two basic reasons why this happens. First, as we grow older there is progressively less newness in our lives. From one year to the next, we gradually use up the store of potential new experiences available to us. Second, as we get older, all the experiences we've already had become more familiar to us. Not only do we have fewer new experiences, but the experiences which are already familiar to us become progressively less real. In William James' words, "each passing year converts some of this experience into automatic routine." As well as experiencing lots of new things, a woman at the age of 20 is still experiences the phenomenal world around her as fresh — but over the next 20 years, she'll look at the same street scenes and the same sky thousands of times, so that more and more of their realness will fade away.
Incidentally, this link between time and information can explain other aspects of time too. One of the "laws" of psychological time which I set out in Making Time is that "time seems to slow down when we're exposed to new environments and experiences." This is because the unfamiliarity of new experiences allows us to take in more information.
Another of the laws is that "time goes quickly in states of absorption." This is because in states of absorption our attention narrows to one small focus and we block out information from our surroundings. At the same time there is very little cognitive information in our minds, since the concentration has quietened the normal thought chatter of the mind. On the other hand, time goes slowly in states of boredom and discomfort because in these situations our attention isn't occupied and thought-chatter flows through our minds, bringing a massive amount of cognitive information.
Time doesn't necessarily have to speed up as we get older though. To a certain extent, it depends on how we live our lives, and how we relate to our experiences. I'll look at this idea in a future blog post.
Steve Taylor is the author of several books on self-development and psychology, including Making Time: Why Time Seems to Pass at Different Speeds and How to Control it.