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PREAMBLE:
I wrote this at 39 weeks pregnant, just days before welcoming baby #2. At the time, I was noticing all the little ways behavioral science shows up in pregnancy and parenting, and I wanted to capture them before life got busy again. Rereading it now makes me realize how much still rings true and how some lessons feel even sharper the second time around. You might be surprised where else they show up in work and life (I am)!
- Kristen
I am pregnant. Like really pregnant. 39 weeks.
As I prepare for my second child, I've been thinking about the behavioral science principles and insights. Today, I'll detour from our normal product and marketing teardowns and share four observations that might help you think differently about parenting, pregnancy. Two are general world observations that you could drop at a dinner conversation and two are actionable tips/lessons you can immediately apply to your life.
The endowment effect: The ultimate ownership bias
Dan Ariely has written about what might be the most powerful example of the endowment effect: how we value our children.
If you went to a park and looked at all the children playing, how much would you pay to buy one of those children? For most people, the amount is not above zero—you simply don't want someone else's child. But if asked how much you would sell your child for? There's likely no number high enough. So offensive.
This illustrates a profound bias: we value what we own far more than identical things we don't own. And nothing demonstrates this more powerfully than our children.
What's beautiful about this is that attachment seems less biological than we might think. Consider pet parents:
I've approached dog owners struggling with high vet bills or behavior problems and innocently asked, "Have you considered giving the dog away?" The reactions are universal: horror, disgust, and shock. This despite the fact that:
They didn't birth this dog
There's no biological connection
They likely chose it somewhat randomly from a shelter or breeder
This powerful attachment to what's "ours" is encouraging as we consider the future of family formation. Whether through adoption, surrogacy, or donor eggs/sperm, the profound attachment parents feel comes from "this child is mine to care for" rather than "this child shares my DNA."
The similarity principle: We're more alike than different
As many of you know, I live in a compound type thing with 6 other families. We like to think our children are unique (and they are in many ways), but they all
Learn that the cow says "moo" around the same time
Go through a phase of moving rocks from one place to another
Develop sleep patterns that follow predictable trajectories
This became especially apparent through our experience with a night nanny named Rosalie. Using consistent approaches to feeding schedules and sleep hygiene (not sleep training), she helped multiple neighborhood babies sleep eight hours by eight weeks—without cry-it-out methods.
Now most parents would say “all kids are different” and you can’t expect kids to sleep through the night at 8 weeks. But Rosalie has shown that may not be all correct. Sure some kids are different, but most are very very similar and the hacks she uses on one, also work on the others!
There's something beautiful about this similarity. The major transitions of human life—birth and death—follow remarkably consistent patterns across all humans. Birth progresses through predictable stages; dying bodies shut down in similar ways.
In a world where we prize individuality, there's something comforting about knowing we're fundamentally similar in our basic human experiences. It connects us across differences and reminds us of our shared humanity.
Communication hack: Talk in months, not weeks
Pregnant women tend to measure progress in weeks: "I'm 28 weeks along." This creates two problems:
It requires mental math from others (How many months is that?)
It obscures progress relative to the familiar 9-month journey
My recommendation: when talking to others about your pregnancy, speak in months rather than weeks.
"I'm six months pregnant" immediately communicates progress in a way everyone understands. Say "24 weeks" and people don't intuitively grasp where you are in the journey.
Why does this matter? Because it:
Makes us feel like we've made more progress
Helps others appreciate our journey more effectively
Might even get someone to carry your bag or offer their seat!
While tracking days and weeks makes sense in your pregnancy app, communicating in months creates better social understanding and support.
The pregnancy announcement experiment
Here's another pregnancy observation: it's LONG. Ten months is a marathon, not a sprint. And it becomes particularly salient in those final months when you're visibly showing, changing clothes, and fielding constant questions.
So we tried something different this time around. With our first child, Phil and I told everyone immediately at five weeks. With this second pregnancy, we decided to keep it quiet much longer.
Why? A few reasons:
The social experiment: Living in a compound with about 20 people, I was curious: Who would notice? When would they figure it out? How long could we maintain the "secret"?
Attention management: By delaying the announcement, we shortened the period where pregnancy dominates every conversation.
Conversational variety: When people know you're pregnant, it often becomes the only thing they want to discuss. By waiting, we maintained more diverse and interesting conversations.
The results were shocking: No one noticed for 6.5 months. Let me repeat that. I live in a compound with 20 people who I see 4-5 times per week, and not a single person noticed I was pregnant for over six months!
This is a perfect example of what psychologists call the "spotlight effect": we dramatically overestimate how much people notice about us.
The phenomenon has been empirically demonstrated in multiple studies. In one classic experiment, students were asked to wear embarrassing Barry Manilow t-shirts to a large introductory psychology class and then estimate how many people noticed. The students consistently and dramatically overestimated the number of people who had actually noticed their shirts.
Despite:
Gaining 15 pounds
Having a visible baby bump
Stopping drinking wine at social gatherings
Absolutely zero people noticed. And trust me, these are people who would have definitely mentioned it if they had! After I finally announced, no one said they had kept quiet out of politeness—they were genuinely surprised.
The lesson? People are far more focused on themselves than on you. So I'll let that stain on my shirt go, wear mismatched socks without worry, and definitely stop agonizing about small acne breakouts or a few extra pounds. No one's paying nearly as much attention as we think they are.
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📧 Questions about product adoption? Shoot me an email: kristen@irrationallabs.com.
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