My cousin fell asleep at the lunch table last Sunday.

Maybe fifteen minutes, head on his arm.

When he woke up, the first thing he said was, “I needed that.”

Nobody had asked.

That was the part I found funny. Somehow even a fifteen-minute nap needed an explanation.

So as always I went looking to see what we actually know about napping, beyond the usual advice about getting more sleep.

Most research on naps has an obvious problem.

People who nap regularly may be different from people who do not. They may be older, sleep less at night, have different health conditions, or simply define “sometimes” very differently.

A 2023 study tried to get around some of that using Mendelian randomization.

Instead of only comparing people who said they nap with people who said they do not, the researchers used genetic variants already associated with a tendency to nap and looked at whether those variants were also associated with differences in the brain.

It is not the easiest study to explain at a lunch table.

The result is.

It also needs a fairly large asterisk…

I wanted to know what other neuroscientists made of it. Dr. Tara Spires-Jones, the then president of the British Neuroscience Association, called the study interesting but pointed to a problem with the genetic method.

The genetic signature associated with napping also overlapped with the signature for some cognitive outcomes. Once that happens, it becomes harder to say with confidence that napping itself caused the brain-volume difference.

The study also began with people reporting their own napping habits, which brings back some of the messiness the researchers were trying to avoid.

So I would be very careful with the headline version of this research. A nap has not been proven to make your brain younger.

There was another finding in the same paper that made that even clearer.

They found no difference in the visual-memory or reaction-time measures.

So there is a brain-volume difference. What that difference actually does for the person attached to the brain is still an open question.

A few weeks ago I had one of those days where one meeting ends and the next face is already waiting on the screen.

At some point I closed the laptop, set an eleven-minute timer and shut my eyes at my desk.

When I came back online, someone asked where I had disappeared.

My immediate instinct was to explain it.

Not even admit I had taken a nap. Explain why the nap had been necessary.

Which is exactly what my cousin had done at lunch.

My grandmother would have found the whole thing ridiculous.

She napped almost every afternoon and I cannot remember her announcing why she deserved it first. Lunch was done, afternoon came, she slept for a bit. End of discussion.

Somewhere along the way, those same fifteen minutes became something I was hiding behind a closed laptop.

Those numbers come from different pieces of sleep research, but they point in the same direction. We are not exactly walking around well-rested.

My grandmother took her fifteen minutes and got on with the day.

I apparently need an alibi.

I'm not going to tell you a nap makes your brain younger. The science isn't settled enough for that.

What I am less sure about is why sleeping for fifteen minutes in the afternoon feels so much worse than spending those same fifteen minutes scrolling through a phone.

One looks lazy.

The other somehow passes as a break.

I doubt my cousin had done any calculation about brain volume before putting his head down at lunch. He was tired, so he slept. My grandmother probably had even less interest in the neuroscience.

Maybe they had the simpler rule.

If you are tired and you have fifteen minutes, sleep.

Hit reply and tell me: who in your family could take an afternoon nap anywhere and never feel the need to explain it?

I read every email.

Until next week,
Ritesh

P.S. Next time you catch yourself dozing off somewhere you shouldn't, say nothing when you wake up. See how strange that feels. That's the actual experiment.