How do you answer a 5-year-old who asks “How much longer until we get there?”

As I was working on the beta version of our long-term decision assessment today, I realized that part of the algorithm can be applied to a question I’ve thought about most of my life: How does our perception of time change as we get older? And if nothing else, the answer to that question helps shed light on the summer road trip conundrum.

I think the answer is related to another common question around our house: ”Daddy, how old is Ruby?” Since Ruby is a puppy, the answer is always in explicit units of human years or dog years. For simplicity around the house, we use the 7:1 ratio as a rule of thumb, meaning 1 human year equals 7 dog years. But anyone who lives around humans and dogs knows that ratio is not quite right, especially when comparing puppies and little kids, and so vets put together a handy chart to provide a more accurate translation. Thus Ruby is ten-months-old in human years and twelve-years-old in dog years. That seems about right.

Everyone understands what it means to translate age between dogs and humans, and because dogs and humans empathize with each other the translation is a strangely interesting topic of conversation.

Why not do the same for people?

Back in college I made up a rule of thumb that our perception of time depends on the doubling of our experience after age 4, meaning that the time periods between ages 4, 8, 16, 32 and 64 all feel roughly the same. I came up with it because I wanted to know how long my life would feel if I lived as long as my Grandpa Lee, a robust man who died in his late-90s. By my calculations, living from birth to my mid-20s would feel roughly the same as living from my mid-20s to late-90s. At the time that prediction had the ring of truth, some of which still echoes around my head, though it seems less important now.

My recent explorations of the current state of cognitive neuroscience and behavioral psychology give me some new data and perspective to generate my own chart. This one is for parents, with the hope that at a minimum it will spark interesting car-trip conversations with impatient 5-year-olds, and perhaps provide a framework for empathy between parents and progeny, or more generally people young and old.

So, if you are a forty-year-old parent, teacher or manager of young employees, one hour for you feels like:

12 hours for a three-year-old
7 hours for a five-year-old
4 hours for a nine-year-old
3 hours for a thirteen-year-old
2 hours for a nineteen-year-old
1.5 hours for a twenty-five-year-old

You can also extend this into the future if you are a forty-year-old child of elderly parents or a caregiver of some sort. Thus, an hour for you feels like 30 minutes to a 70-year-old and 20 minutes for a 90-year-old.

The algorithm I used is based on how learning, development and sleep patterns change over time, so I think it models reality in some sense. However, to keep things on the level, I do not believe is reasonable to translate literally between the perceptions of children and adults any more than it is reasonable to expect a ten-month-old puppy to act like a twelve-year-old child. And the fact that time flies when you are having fun and a watched pot never boils also throws a wrench in the works when you driving a beautiful mountain road with a couple of kids in the back seat. Perception is a tricky thing.

Nonetheless, the next time you are asked “How much longer?” maybe asking “Do you mean in parent minutes or kid minutes?” will put things in perspective and buy you some time.