The Secret Physics of Love: Why Joy Matters More Than You Think
Sunday, August 17, 2025.
Physics has the Big Bang, quantum entanglement, and black holes that swallow time itself.
Psychology? We get “smile more, it helps.”
It’s not a fair fight.
And yet, every now and then, psychology coughs up an idea that feels suspiciously like a natural law—a principle that explains why marriages survive, families adapt, and love doesn’t just collapse under the weight of modern life.
One of the main culprits here is Barbara Fredrickson, a psychologist who took the audacious step of studying happiness in a field sorta obsessed with misery.
She gave us three ideas—Broaden and Build, Upward Spirals, and The Undoing Hypothesis—each sounding like the title of a self-help workshop but backed by actual data.
Taken together, they form what I like to call the secret physics of love.
Let’s walk through them, gentle reader.
Chapter One: Broaden and Build—Or, Why Smiling Isn’t a Waste of Time
Fredrickson’s first breakthrough, the Broaden and Build Theory, argued that positive emotions don’t just make you feel good; they expand your field of vision.
Joy, curiosity, gratitude—they broaden your awareness, letting you notice possibilities you’d otherwise miss.
And once you see more, you can build more—social connections, personal skills, even cardiovascular health (Fredrickson, 2001). Think of it as emotional infrastructure.
In other words, fear keeps you alive in the moment; but joy helps you plan for next year.
Marriage Therapy with a Wide-Angle Lens
In couples therapy, Broaden and Build explains why happy couples don’t just tolerate each other better—they actually see each other differently.
Positive emotions act like a wide-angle lens: instead of noticing only the dirty dishes, you also notice the partner who bought the coffee and walked the dog. Gratitude isn’t soft—it’s adaptive.
Families as Construction Projects
For families, broaden and build means laughter and warmth aren’t extras; they’re scaffolding.
Kids raised in households with more joy develop stronger peer networks, higher academic performance, and greater resilience (Tugade & Fredrickson, 2004).
Positive emotions don’t just decorate family life; they sustain it.
The Joke in All This
Of course, broaden and build won’t pay your mortgage. It won’t soothe your crying baby at 3 am.
But without it, you don’t even see the doors that might lead to solutions. Positive emotions don’t solve the mess, but they give you the vision to navigate it.
Chapter Two: The Upward Spiral—Staircases, Not Fireworks
Having broadened and built, Fredrickson proposed another metaphor: the Upward Spiral.
Positive emotions don’t just accumulate, they feed on each other.
One laugh leads to connection, which sparks more laughter, which deepens connection.
Repeat until you have something that looks suspiciously like intimacy (Fredrickson, Cohn, Coffey, Pek, & Finkel, 2008).
Staircases vs. Fireworks
In marriage counseling, my clients come in wanting fireworks—one grand breakthrough fight that rewrites decades of resentment.
Hopefully, what they get from working with me more resembles a staircase.
In other words, connection occurs in micro-moments: a kind word, a shared joke, a hand brushing a shoulder.
The Upward Spiral says these aren’t trivial—they’re the actual mechanism of relationship growth.
Family Spirals at the Dinner Table
Families can run on upward spirals too.
A laugh at the dinner table spirals into greater peer confidence at school, which spirals into resilience in friendships, which spirals back into family warmth. Even grandparents contribute—sharing play and affection that rejuvenates both them and the kids.
Spirals Go Both Ways
Of course, spirals can just as easily go down.
Sarcasm spirals into defensiveness, defensiveness into resentment, resentment into distance. Before long, you’re living with a roommate who hates your playlists. Momentum is merciless—it doesn’t care if you’re headed up or down.
Why Spirals Matter in 2025
In our culture of doomscrolling, distraction, and constant hustle, the upward spiral isn’t luxury—it’s resistance.
Small nudges of shared joy are how couples and families resist cultural entropy. Forget the grand romantic gesture; start the spiral with a smile.
Chapter Three: The Undoing Hypothesis—Joy as Nervous System Reset
Finally, Fredrickson gave us the Undoing Hypothesis—the idea that positive emotions don’t just make you feel good, they actively reverse the physiological effects of stress. Fear spikes your blood pressure; joy lowers it.
Anger tightens your chest; laughter loosens it (Fredrickson, Mancuso, Branigan, & Tugade, 2000).
Stress is Sticky
An argument with your spouse doesn’t end when the words stop; your nervous system keeps racing long after. Positive emotion is the reset button.
Undoing in the Therapy Room
In my couples therapy work, I’ve seen this play out again and again.
A couple is mid-fight, the room thick with cortisol. Then one of them laughs—maybe at me, maybe at each other. The tension collapses. Their nervous systems calm down enough to talk like human beings again. That’s what undoing looks like in real time.
Families and Micro-Resets
For families, undoing explains why silliness works better than lectures.
Parents who lighten discipline with humor aren’t weak; they’re teaching their kids’ bodies how to return to baseline. Grandma’s advice—“make them laugh and they’ll forget why they’re crying”—turns out to be backed by cardiovascular data.
The Catch
Undoing doesn’t erase the cause of stress. A sitcom won’t balance your checkbook.
But it does buy time, giving you the clarity to address problems without a nervous system screaming “tiger!” when it’s just the gas bill.
Why These Three Ideas Matter Together
Taken as a set, Fredrickson’s ideas form a quiet theory of survival for marriages and families:
Broaden and Build tells us why joy matters—it widens the field.
The Upward Spiral shows us why small moments matter—they accumulate.
The Undoing Hypothesis explains why laughter heals—it resets the system.
They’re not flashy, but that’s the point.
Love isn’t physics on the scale of galaxies—it’s physics on the scale of kitchens, dinner tables, and arguments about who left the lights on. And maybe that’s more important.
Physicists can marvel at collapsing stars. Psychologists, meanwhile, found a more useful and immediate miracle: joy is the human nervous system’s reset button.
Be Well, Stay Kind, and Godspeed.
REFERENCES:
Fredrickson, B. L. (2001). The role of positive emotions in positive psychology: The broaden-and-build theory of positive emotions. American Psychologist, 56(3), 218–226. https://doi.org/10.1037/0003-066X.56.3.218
Fredrickson, B. L. (2013). Love 2.0: How our supreme emotion affects everything we feel, think, do, and become. New York, NY: Hudson Street Press.
Fredrickson, B. L., Cohn, M. A., Coffey, K. A., Pek, J., & Finkel, S. M. (2008). Open hearts build lives: Positive emotions, induced through loving-kindness meditation, build consequential personal resources. Journal of Personality and Social Psychology, 95(5), 1045–1062. https://doi.org/10.1037/a0013262
Fredrickson, B. L., Mancuso, R. A., Branigan, C., & Tugade, M. M. (2000). The undoing effect of positive emotions. Motivation and Emotion, 24(4), 237–258. https://doi.org/10.1023/A:1010796329158
Tugade, M. M., & Fredrickson, B. L. (2004). Resilient individuals use positive emotions to bounce back from negative emotional experiences. Journal of Personality and Social Psychology, 86(2), 320–333. https://doi.org/10.1037/0022-3514.86.2.320