How psychology explains the itch for spring cleaning

Wharton Professor Katherine Milkman teases out the “fresh start effect” of temporal landmarks like the first day of spring, New Year’s Day, and other meaningful calendar dates.

Katherine Milkman

Love it or hate it, spring sweeps in—along with the pollen and dander—a flurry of fresh starts.

Cleanups, decluttering, thematic rebirths. Perhaps more than any other season, spring draws a line in the sand between old and new. It’s what Katherine Milkman, a Wharton professor, behavioral economist, and decision-making scholar, would call a “temporal landmark.”

The term, borrowed from Michael S. Shum’s 1998 research on “autobiographical memory,” says that some dates, more than others, “stand in marked contrast to the seemingly unending stream of trivial and ordinary occurrences.” Spurred by this notion, plus an inspiring meeting with a Google human resources team several years ago, Milkman utilized a combination of data analysis and survey experiments to test a hypothesized “fresh start effect”—that is, that individuals feel more motivated to set and execute their goals when they are marked by socially meaningful calendar dates, like spring or New Year’s Day, or personal life events like a birthday. 

To tease this out, as the days turn warmer and sunnier and the calendar greets the first days of spring, Milkman discusses some takeaways from her aspirational behavior research and laboratory experiments, and how the simple reminder of spring, in particular, demonstrated significant goal-setting behavior among test subjects.

For starters, how would you explain the concept of the ‘fresh start effect’ you reference in your research?

The basic idea is that we have ebbs and flows in our motivation, and the ‘fresh start effect’ gives us insight into times when our motivation is likely to be particularly high. We all have intuition that the start of a new year, for example, is a fresh start or new beginning—a time to kick-start new things. New Year’s resolutions are widely adopted. There’s, of course, a social pressure element to that as well, but part of it is you feel as if last year’s failures are behind you—that you have a clean slate, a fresh start, an opportunity to achieve the things the old you failed to achieve. 

So, this concept of ‘fresh start’ is built on the premise that New Year’s is not the only moment that gives us that sense; there are many moments like that throughout the year. The start of a new week, or month [or season]; the start of a new period in our lives because there’s been a holiday that separated us from our past selves. Or a birthday. Those are all fresh starts.

The first day of spring was part of your 2014 research and had some interesting insights. You did a controlled experiment testing whether goal-motivated people were more likely to set a goal reminder on ‘March 20 (Thursday; The Third Thursday in March 2014)’ or ‘March 20 (Thursday; The First Day of Spring 2014)’ when prompted, and it turns out they were more likely to choose the first day of spring—3.54 times more likely, in fact.

That’s right. A new season is a new cycle. 

One thing interesting about new seasons is I don’t think they are as obviously fresh starts as some other landmarks. Like Mondays [with dieting]. Everybody really feels like ‘OK, new week, new cycle.’ New Year’s has that same feature. First days are salient to people. 

But then there are other, ‘sleeper’ fresh starts, if you will, where not everyone is focused on them as an opportunity. But if you draw attention to them, you can really have a big motivating effect. Spring is a nice one we’ve used because people are not automatically, by default, thinking of spring as a time to start new habits. But if you mention that it’s an opportunity or emphasize the opportunity—‘Hey, spring is a good time to do things differently’—just that can have a big impact.

They’re not obvious, but they make sense to people if you cue them. A lot of our research is on nudging, or changing people’s behaviors for the better, and there’s a bigger opportunity with things like spring that I’m not already focused on—for me to use it as a nudge and try to bring it to your attention and change behavior.

A lot of this research seems based around ideas of the self—on wanting to distance the current or future self from the past self. Painting an image of an imperfect self, marked by these moments in time.

We generally like to have a vision of ourselves as on an improvement trajectory. One wants to think they’re not getting worse over time. So, it’s easy to throw your past self under the bus. We’re comfortable doing that. ‘The old me was terrible, but I’m not like that anymore.’ We like to have a positive self-image, but having a negative image of our past self is OK because that past self is gone. Fresh starts give us the opportunity to throw the old self under the bus. It disconnects us, feels further behind—before New Year’s was ‘last year’s me,’ or ‘That was winter me—spring me will be different.’ That’s one thing we think contributes to fresh starts and the way they influence us.

Any sense of what the window period is for how long these temporal landmarks make us feel more motivated?

In one of our papers, we mapped out some of the decay rates and it varied. Tuesday is fresher than Wednesday, and Wednesday is fresher than Thursday. In the course of a week, it was kind of a step function. It’s not like ‘Monday is fresh, and the rest not.’ But then others peaked for just a day. I think we didn’t see an effect for searches on diet with spring, and it’s one of the reasons we used that as a lever, because it didn’t seem like ‘We’re naturally taking advantage of it.’ But it seemed like something we could get people to take advantage of … 

I can’t say for sure how long the spring fresh start effect lasts, but I imagine it’s longer than a day.

Do you think there’s a difference between the seasons, in how much more motivated they make us feel?

Probably. That’s one thing that’s funny about this—it’s not like all fresh starts are created equal. Some resonate for various reasons. By far the biggest is New Year’s. It has all the things we just talked about. A year is more substantive than a week or a month. And it has a social component. We’ve normalized it as a time to have resolutions. And I imagine, for students, fall is a really big fresh start because they’re starting a new academic year, so it’s sort of like New Year’s and associated with routines changing. I think it’s going to depend on the person and what resonates with them, but spring is a more natural fresh start for people than winter—spring is the season of rebirth and Easter and everything is green. That’s probably more psychologically resonant. But that’s probably smaller than birthdays, which are more personal and meaningful. Everyone is a little different.

We had one set where we looked at the Jewish New Year, which, unsurprisingly, is motivating for people who are Jewish and not at all for people who aren’t. It depends what’s meaningful for you. All fresh starts are not created equal.

What do you think are the practical implications of having the knowledge from your studies that people are more motivated and set more goals when in tandem with these temporal landmarks? Whether spring, New Year’s, birthdays, etc.

We look at it as an opportunity to help people. So, two things: The research came about because I gave a talk at Google, for their HR team, about some of my other work that preceded this on ways we can follow through on people’s best intentions to get a vaccine, or flu shot, or get a colonoscopy—to do the things they know they’re supposed to do and are good for their productivity and happiness. And the head of HR said, ‘We’re sold we should be using these tactics to try and help people save for retirement, to get healthier, et cetera, but is there a good time to deploy them? When do we send reminders or start programs, or get people to make changes in their lives that are healthy and good for them?’ And I was like, ‘Oh! What a great question. We don’t know the answer to that.’ And so that’s what sparked the research, really, a practical question. 

I think the answer to ‘How is this research useful?’ is to answer that question. If we as a society are trying to [improve] public health campaigns or organizations are trying to get employees to take educational workshops to improve language skills, or getting people to save more for retirement, all these campaigns we make to help people do things in their best long-term interest but often procrastinate on. This research suggests moments when people are particularly open to change. That’s when we should market the programs that exist or release new things. 

And they also provide an opportunity to change behavior by just highlighting those fresh starts—that they are an opportunity. 

And as cynical as folks can get about resolutions and spring cleaning, the mindset does work for some people.

Whatever it takes for you to try and make change. All of us have vices we’d like to get rid of. A lot of my work is on health, and it turns out 40 percent of premature deaths in the U.S. are the result of behaviors people could change. Not taking medications, not being physically active, drinking too much, smoking cigarettes; those are huge numbers. 

If we can get even a small number of people to make changes that would change their lives, that’s a huge deal.