So when I was a kid on family road trips, my Mum would keep a bag of lollies in the front seat with her.

And when I’d ask for one – she would make me practice “delaying gratification.” So instead of giving me and my brother one now, she’d make us wait until the next town and then she'd give us two.

Now, this wasn’t just because parents are mean when it comes to road trip snacking.

She genuinely believed that kids who practice self control grow up to be more successful adults.

This idea is based on a classic psychology study – but now this study is in some hot water because it can't be replicated.

So is there truth to the benefits of delayed gratification?

It all started with a study called the “Marshmallow Test.” In the late 1960s, Professor Walter Mischel at Stanford University ran an experiment where he gave preschool kids a treat, in this case a marshmallow, and told them that if they waited 15 minutes until he got back to eat it, they’d get a second one.

Then he’d leave the room.

Some kids waited the full 15 minutes and got two marshmallows, and some kids ate theirs before he returned.

The study checked back in with these kids years later to see how they did academically, socially, and professionally.

What Mischel saw in follow-up studies was that kids who were able to delay gratification were described as more competent teenagers and had higher SAT scores.

The public went a little nuts.

And it wasn’t just my Mum, lots of parents heard about this study.

People were fascinated by the idea that a single skill: the ability to exercise will power and delay gratification, could predict how successful their preschooler would be later in life.

But, as always, we’re right to be a little skeptical.

So this study tracked 90 children, all of which were enrolled in the preschool at Stanford university.

What would happen in a different setting?

To find out, another group of researchers recreated the study with over 900 kids from a wide range of social, cultural, and family backgrounds.

They also looked at other possible explanations for both a child’s ability to delay gratification, and for their future success.

No one doubted that preschool willpower and adult success were linked, but... was early willpower the only cause of this success?

What they found was that things like family income and home environment better explained if kids displayed willpower and then if kids were more successful later in their life.

For example, in homes where the mother had a college degree, whether or not the child waited for a second marshmallow was completely unrelated to how they did in the long run.

In homes where mothers didn’t have a college degree, the family’s income and home environment seemed to determine both how long a child waited, and how well they did down the line.

If a kid struggles with food insecurity at home, it’s understandable both that they’d eat the marshmallow without waiting, and that they’d have more difficulties as they got older.

People thought that the marshmallow study was a groundbreaking piece of evidence that displaying self-control early in life would lead to a brighter future, but underlying the study was human error.

You had a group of upper middle class researchers working with upper middle class subject and the results couldn’t be replicated for kids from different socioeconomic backgrounds.

What it really shows is how our early childhood environment can impact both our behaviour and our potential.

And looking beyond a single skill like self-control, things like creating a nurturing learning environment, having academic materials and role models can all help to set up all kids for success.

Success comes from a variety of influences, and one way that we can better understand it is to have researchers from all different backgrounds and location collaborating and working together.

That’s how we get better science, and it's also how we can all convince my Mum that I should be able to have marshmallows whenever I like.

Thank you to Chevron for supporting this episode.

Chevron focuses on improving instruction in STEM (Science, Technology, Engineering and Mathematics) as well as providing career and technical training that can lead to well-paying jobs.

To learn more, you can head to www.chevron.com/education.

Thanks!