[mattlondon]

It seems to vary a lot in my experience. I have two kids who basically got the same treatment. One was eloquently talking in coherent sentences of 4 or 5 words by 18 months ("plane in the sky", "teddy come downstairs", "want something to eat" etc) and was understandable by others outside the family, the other kid was barely able to grunt single words at the same age ("mukk" instead of milk, "nur-sa" instead of nursery etc) that only we really understood as it was just incomprehensible sounds to everyone else

Singing made fuck all difference in that case (FWIW, the grunter is now totally fine as an older kid). Both were walking at 10 months so it was not like one was just "slow" at their milestones

As they say, every baby is different.

[pstuart]

Yep. Having more than one kid disabuses us of the notion that our parenting was the driver in how awesome the kid turns out.

That said, I believe it's nature and nurture in the end.

[e1g]

Same here, two kids and zero strategies that worked with one apply to the other. Might as well be raising a dog and a dolphin.

[CSMastermind]

> Might as well be raising a dog and a dolphin.

That made me chuckle.

But it's possible for siblings not to share any genetic material right?

A brother and a sister would obviously get different genes from their father and presumably there would be a 50/50 chance of them getting different genes from their mother.

There's four unique prototypes of children any two people can produce together.

[harry_ord]

> But it's possible for siblings not to share any genetic material right?

Kinda but the mother always provides the mitochondria.

[CSMastermind]

I think that's an area of open research: https://www.pnas.org/doi/full/10.1073/pnas.1810946115

But yes, that's a good distinction I should have made!

[harry_ord]

Oh that's cool. Now I have something new to read thanks.

[caseymarquis]

I thought it was more like 2^23 unique prototypes?

[darkerside]

Four prototypes?

[danwills]

Gamete cells get a random half of all genes from each parent so there's about 2 unique possible 'sets' from each parent, and 2*2=4. However because it's random I think you can only say there are 4 distinct completely unique possibilities in theory, but it would be very unlikely for that to actually happen in practice.

[diroussel]

Each parent supplies half the genetic material. But each sperm and each egg have a randomly different set of one half of each chromosomes. So if you have 10 children chances are they each have a unique set of chromosomes.

[darkerside]

Ahh, as in fully exclusive sets of genes

[fsckboy]

>Four prototypes?

gp said four unique prototypes

[rand0mx1]

Probably genotype. Isn't it

[tbcj]

My experience as well. My two are so different it’s hard to even parent at times as they need different kinds of attention. You can’t really give yourself in different ways at the same time. We recognize that one - being born in the lockdown environment - is likely different in meaningful ways than our first. Our first is helpful in she almost recognizes a difference.

[jascination]

Same. Have twins (fraternal) and their milestones are completely different despite pretty much identical treatment all things considered. They're also naturally better at certain things (twin A better at physical milestones, twin B better at social milestones).

[pstuart]

Fraternal twins as well -- night and day.