How an Advent Calendar Became Our Kids’ Marshmallow Test

Patience, culture, and chocolate: a parenting experiment in delayed gratification

My children are now 4.5 and 2.5 years old, so during our weekly visit to Trader Joe’s today, we thought they were ready to both have their own advent calendar.

Some people get surprised when they see this in my older child: he can wait to eat a treat for hours or even days if asked to do so. He proved this after Halloween’s trick-and-treating and on many other occasions. If you tell him he’ll need to wait until the next day, he will. But expect this to be the first thing he asks about after he wakes up. 

However, with my younger one, we weren’t so sure. She’s the child who will climb on kitchen cabinets to get all the treats at once. 

Sure thing, they both acted as anticipated. 

My 4-year-old carefully opened all windows, curious about what’s coming each day. However, he only ate the one for the day and notes what shape’s tomorrow. When he woke up on December 2, he repeated the exercise, eating a single chocolate: what was behind number two? 

What about my 2-year-old? Well, she was a completely different story. The second I turned around, she started opening as many windows as she could and immediately eating them. Her patient brother warned me but didn’t copy her. 

So I took the advent calendar from her, and reminded her of the rules: One chocolate a day, you need to wait until tomorrow to eat another chocolate. You won’t have a chocolate piece for the days you already ate. 

I wished I could say this was the end of the story, but a second part of the saga awaited us this morning. After waking up, I noticed she wasn’t around, so I went downstairs to find her. She had sneaked to the kitchen, grabbed her calendar, and eaten a few extra pieces. She smiled at me and claimed to regret nothing. 

Why the different behaviors? Well, I thought that to begin with, she is two years younger than her brother. On the other hand, we didn’t introduce my older child to sweets until he was old enough to understand what was going on at birthday parties and celebrations. My daughter was still a baby at that point, but she learned what sweets were a lot earlier. 

I’m a scientist, so I got curious. This reminded me of the Marshmallow Test. Did this mean that my older child was going to be more successful than my younger one? Is this an age thing or something else?

For decades, the marshmallow test has been a staple of psychological research, used to gauge self-control in kids and predict their future success. A preschooler faced with the choice to eat one marshmallow now or wait to get two later — it’s simple, right? 

But before we move on with the story, here’s a brief summary of the Marshmallow Test:

The Marshmallow Test is a classic psychological experiment designed to study delayed gratification. Developed in the 1970s by Dr. Walter Mischel, it involves offering a preschooler a choice: they can either eat one marshmallow immediately or wait a set period (typically around 15 minutes) to receive two marshmallows. 

The test aims to measure self-control and the ability to resist immediate temptation for a larger future reward. Does it sound relatable to adult life? Well, it is. Keep reading.

Follow-up studies suggested that children who waited longer tended to perform better later in life, showing higher academic success, better health, and stronger social skills. However, more recent research highlights the influence of cultural and environmental factors on the results.

For example, a recent study shakes up this classic framework, revealing that culture profoundly influences what children are willing to wait for.

In fact, researchers found that children in Japan and the United States approach the concept of delayed gratification differently, shaped by the habits they grow up with. 

Japanese children showed impressive patience when waiting to eat sweets, while their American counterparts excelled at waiting to open gifts. “What kids are willing to wait for depends largely on their cultural upbringing,” said Dr. Yuko Munakata, a senior author of the study and researcher at the University of California, Davis.

Let’s look at this new take on an old classic study, shall we?

The study involved 138 preschoolers from Kyoto, Japan, and Boulder, Colorado. The children were randomly assigned to one of two scenarios: resist eating a marshmallow or resist opening a wrapped gift. 

Before that, though, parents completed surveys to assess the children’s habits and sensitivities to social conventions, and researchers monitored the children’s wait times through video feeds.

But what made this study unique compared to the hundreds of other studies looking at the same question?

This study focused on cultural habits rather than individual traits. Japanese customs emphasize waiting to eat — whether it’s the tradition of saying “itadakimasu” before meals or waiting for everyone to be served. In contrast, American traditions, such as waiting for Christmas morning to open gifts, teach patience in different contexts.

And what did the results have to say?

Well, Japanese kids waited three times longer to eat the marshmallow than to open a gift. Conversely, American kids waited nearly four times longer to open a gift than to eat the marshmallow. 

These differences reflect the cultural habits ingrained in each group. For example, as Dr. Munakata explained, “In Japan, no one eats until everyone is seated,” while in the U.S., kids are often encouraged to hold off on opening presents during holiday celebrations.

I didn’t grow up in America, and I’m always surprised to see gifts under the tree for days and kids patiently waiting. This wouldn’t happen back home!

But the study went deeper. Children who were more attuned to social conventions — like waiting for everyone to start eating — were better at delaying gratification in culturally aligned contexts. 

In Japan, this meant waiting to eat. In the U.S., it meant waiting to open gifts. “This suggests that the way you grow up, the social conventions you are raised around, and how much you pay attention to them are all important,” said co-author Dr. Grace Dostart.

Interestingly, the study challenges the idea that self-control is purely an inherent trait. Instead, it shows that habits can play an equally important role. 

For instance, Japanese children’s patience with food wasn’t necessarily a sign of superior willpower — it was a reflection of the cultural practice of waiting for meals. Similarly, American kids excelled at waiting to open gifts because of their traditions around gift-giving.

But what should we take away from this as parents or caregivers? 

The researchers emphasize that it’s not just about teaching kids to say no to temptation — it’s about fostering habits that align with their cultural values. Encouraging children to wait for others at mealtime, for instance, doesn’t just teach politeness. 

According to Dr. Munakata, it may even “change brain systems in ways that make delaying gratification more automatic.” In other words, these habits could set kids up for success in a variety of future challenges.

For researchers, this study is a reminder to consider the cultural lens through which behaviors are studied. The classic marshmallow test was long thought to reveal universal truths about self-control, but it may have overlooked the role of cultural context. Indeed, future studies can paint a more complete picture of human behavior if they acknowledge cultural differences. 

This research highlights the power of everyday practices in shaping children’s ability to wait for rewards. It’s not just about biology or cognitive ability — culture and habits matter, too. 

Whether it’s waiting to eat until everyone’s ready or holding off on tearing into holiday gifts, these traditions teach patience in ways that resonate deeply within each cultural context. For parents and caregivers, the lesson is clear: simple, every day habits can prepare kids for challenges far beyond the dining table or the gift pile.

And from my own perspective, this study helped me calm my anxieties as a parent. The reason my older child performed better with the Advent Calendar wasn’t necessarily that he is better at delay gratification, and my daughter isn’t already doomed to a lifetime of failure. 

Simply put, my son has been exposed to our family culture for two extra years. Our parenting style has helped him get to this point and, hopefully, my daughter will behave the same in a couple of years. 

Only time will tell, but as parents, we should keep working on their education while being aware of the science behind parenting. 

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Also Published in my Medium Publication STEM Parenting. Follow to learn more about a science-based approach to education.