Negative Correlation Theory of Parenthood

I usually don’t spout scientific theory…but I was recently asked to do a review of “The Science of Parenthood” by Jessica Ziegler and Norine Dworkin-McDaniel, and as a result, have come up with my own theory of parenthood.  I am qualified to espouse this theory – because a) I have a Bachelor’s degree in Social Science and b) I am a mother of THREE children.

The Negative Correlation Theory of Parenthood

My own personal experience (and anecdotal experience from friends and relatives) supports my supposition:  there is an inverse relationship between the increase in the number of children you have and a proportional decrease in the amount of “stuff” (yes, that’s a scientific term) that you need for them.

Evidence To Support Theory – Child #1

With Puck, (Baby #1), for every trip, even to the grocery store, I always had:

  • Baby:  wearing clothing including (if necessary) jacket and shoes and/or snowsuit with hat, gloves, boots, one soother, attached to his bib
  • Stroller with extra pockets and cup holders with rain or snow cover handy AND baby carrier (in case I wanted to push the stroller AND carry the baby)
  • Large purse containing:
  • Wallet including all health information including vaccines
  • Cell phone
  • Phone book with all emergency phone numbers
  • Small calendar
  • A LARGE Diaper bag containing (at a minimum):
  • 10 diapers
  • A full bag of wipes
  • Extra jacket
  • Two extra outfits
  • Three bottles and extra formula (I was breastfeeding, but supplemented)
  • A stylish breastfeeding cover
  • Jars of food
  • Three sterilized spoons in a sandwich bag (and an extra sandwich bag for the dirty ones)
  • An extra soother in it’s own container
  • Three bibs
  • Containers with baby cookies and Cheerios
  • A board book
  • His Rufus and a spare (a stuffed dog that went everywhere with us – and I bought seven of them after he attached and we always had at least two in case one got dirty or lost)
  • Kleenex
  • Plastic bags (for dirty diapers or clothes)

Child #2

When Flower was born, for (mostly) every trip, even to the grocery store, I always had:

  • Baby:  wearing clothing including (if necessary) jacket and/or snowsuit (minus hat, gloves, and any footwear), one soother attached to her bib
  • Second hand Joovy double stroller (no rain or snow cover…) AND/OR baby carrier
  • Smaller purse containing:
  • Wallet
  • Cell phone (with emergency numbers programmed)
  • Small calendar
  • Smaller diaper bag containing (at a minimum):
  • 2 diapers
  • A small travel wipe container
  • An extra outfit
  • One bottles and extra formula (still breastfeeding, and supplementing)
  • A stylish breastfeeding cover
  • Jars of food
  • A spoon
  • Two packages of baby cookies
  • One bib
  • A Rufus (which luckily she attached to too)

Notice – the list has decreased in length by about 1/3.

Child #3

By the time Bae was born, we had:

  • Baby:  wearing clothing with jacket if necessary (no extras – and no soother, Bae sucks his thumb which doesn’t add to our carry on…)
  • A small fold up stroller (to which I attached the carseat) – snow cover attached if necessary OR baby carrier
  • Small backpack purse containing:
  • Two diapers and some wipes
  • Formula and a bottle
  • If I was lucky – a container of Cheerios (otherwise, I’d just scrape up whatever was left in his carseat or find somewhere that sold french fries if he was hungry)

Note that again, the list has again decreased proportionally by about 1/3.

Now Bae is two and still in diapers, but we’ve actually gone out with me forgetting to bring extra (I’ve since packed an emergency one in the car – cause that’s not happening again…). He usually has one of his die cast cars and can eat fast food – so I’m happily back to a “normal” sized purse. And sometimes we even just go out with my phone and my keys (the cover has my drivers license and credit card in it).

Subsequent Children

Unfortunately, I won’t be able to confirm my theory with child number four due because we “fixed” that issue.  I suspect if that did happen though, I’d just strap him or her to my back and (maybe) throw an extra diaper in my pocket.  To further confirm my theory – I invite you to provide anecdotal evidence in the comments below – how much stuff did you bring with each subsequent child?

The Science of Parenthood

The inverse relationship between the number of kids and the amount of kids stuff you carry might be my own theory, but you can find similar scientific and mathematical concepts in the book “The Science of Parenthood” – a hilarious book by co-authors Norine Dworkin-McDaniel and Jessica Ziegler.  The book drills deep into the core sciences to explain everything parenthood from pregnancy to birth, toddler to teen including:

  • Occam’s stroller
  • Newton’s Third Law of (E)motion
  • Poopology 101

And find the answers to mystifying questions like:

  • Why do children grow up fast, yet a game of Candy Land drags like a using a rope to pull an airplane?
  • When is your child most likely to poop?
  • How much alcohol does it take to get through your kid’s favorite children’s cartoon?
  • Why every parent needs a fallout shelter?

If you’re looking for a baby shower gift or birth control for your younger sister – this book is your ticket!  See the link below to purchase on Amazon or find more information on Facebook, Instagram and Twitter!


  1. Ha! I’m pretty sure I’ve witnessed this with how prepared everyone is with Niece and Neff. When it was just him, there was a TONNE of stuff to remember, now there are two of them, it’s like, one bag. Maybe.

    The thing *I’ve* noticed is something I think I’ll call “The relative expectations juxtaposition”, which covers all manner of things like how they’ll pick stuff up for me, but not at home…or eat vegetables for grandma, but not for me…or bake nicely at home and make a horrendous mess anywhere else…

  2. I loved your detailed account of the book. I’m reading it now and loving it.

  3. I stopped at two, so far, but I did find a big dip. Even now with him being three, I remember dressing Scarlet more up at age three to go out during winter.
    Science of Parenthood is amazing!

  4. If you have a fifth or sixth child will it be carrying you around the grocery store? I think I might have stopped making babies too soon!

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