If over the last 3 generations.

[Theodoreb]

People were only allowed two children would you exist?

I wouldn't my nan was child number 5
My mum child number 2
And I was child number 1.

No!
I'm 1
DPs 1 or 2
GPS 1/5/?/3?

My husband would be here though, as he and his father were only children and his mother was a second child.

No, neither would DH

No. My df was a fifth child and I am fourth child.

I would as all four of my grandparents were the eldest siblings, my dm was the eldest and my df was the second born.

Df family are Irish Catholics so massive families (think between 6-14 children until my df and his siblings who had between 0-3)

Only one of my cousins would exist.

No my grandparents were from families of 4 or 5, not including any who died young.

Mum youngest of 4. Dad 2nd of 4 though.

It's massively dropped off in my generation. Many of my cousin's are childless, 3 of us just have 2 each.

No, my dad was the 3rd (and last) child for my grandparents.
My mother was the 3rd but child 2 was stillborn. There were no other children later as my gran was in her 40s when she had my mum.
I'm child 1 of 2 for my mum, my dad had a 3rd child with his second wife.

I've thoroughly researched my family tree and most of my family had just a couple of children and waited quite late (late 30s/early 40s) to have them. I've done the same but only have 1 child and won't have more. My DP is child 2 of 2.

The world is over populated and I would 100% back a child cap.

Yes. All twos and dad was a first born of three.

Yes, all twos.

Neither DH or I would be here

No. My parents were numbers 4 and 5 of 9 (my parents aren’t sibling! both their parents had 9 Dc)

I’m not sure what position in the family order any of my grandparents were.

Yup!!
Maternal Gparents - both eldest (1/4 & 1/1)
Paternal Gparents - Uncertain as has no contact
Parents - M (3/3 but 2nd twin) D 1/7
Me - 1/2

I was so close!

All my grandparents were 2nd child of 4-6

My mum is 2nd child of 4

But my dad was 3rd child of 3! I nearly made it!

Firstly, Europe's birth rate is currently 1.5 children per mother and has been below 2 since the mid 70s. ~20 % of women in the UK don't have children at all. The world's birthrate is 2.4 and has also been dropping for the last 60 years . Secondly, if you do want to reduce the population the best thing is not to cap it but to improve women's rights and education and access to contraception. Once women have options they delay (or opt out of) parenthood and reduce their family size without any political pressure to do so.

Having said all that, I'd not be alive because at least 1 of my grandparents was too far down the family tree.

DH would be here though. All his family are very small (no more than 2 children up to 3 generations which I believe was quite uncommon)

All his family are 2nd child other than his dad who is the first. He would've had an easy ride here!

Me: 3rd of 4
DM: 2nd of 7
DF: 6th of 6
DGM (m): 1st of 8
DGF (m): 4th of 11
DGM (p): 3rd of 5
DGF (p): 2nd of 2

So, no.
Looking at this, we are an environmental train wreck. And we aren't even the most populous branch of the family (maternal great aunt had 15 children, for example).

Just to clear up I have no agendas about population control I have 3 dc myself just was curious how badly it would have effected the world we know today if a 2 child cap had been introduced.

I have 2 DC
Me: 1st of 2
DM born 1956: 1st of 5
DF also born 1956: 5th of 5
DGM(m): 1st of 2
DGF(m): 2nd of 2
DGM(m): 2nd of 2
DGF(f): 1st of 3

DH's numbers would be similar, his mum comes from a family of 5 as well but grandparents not such big families. I think you can really see the "baby boom" of the post-war years in our generational sizes.

None of the cousins in my generation have more than 2 kids and about 1/4 don't have any.

If it cancels each other out I would as in my mum is the youngest of three but my dad is an only child?

Ha! No. I'm the youngest from a blended family totaling 8 children, 3 step siblings on my dad's side, two steps on my my mums, two full siblings plus me.

Dad was one of four, mum one of seven and their parent's families were larger still.

I am 50+ and dad was over 50 when I was born though.

BTW we have one child, intentionally.

@Theodoreb

Just to clear up I have no agendas about population control I have 3 dc myself just was curious how badly it would have effected the world we know today if a 2 child cap had been introduced.

I guess it depends on the year you introduced it, not the no of generations. If I'm 20 and have two kids, my mom might be 40 and my granny 60. Possibly even 18, 36 and 54 so affected by a policy from 1960 onwards Vs me being 40, my mom being 80 and grandma being 120 so a policy from the turn of the previous century.

What about second marriages?

My dad is first born but my mum is 5th born to my Nan, but it was a first baby between her and my grandad.

I’m first born too

No.

My grandma was 5th of 5
My mum was third of 3
.
I was first of 2 though

Not even close.
Maternal grandparents were both onlies, and my mum was the oldest, all good. My dad was oldest of two, so again, all good.
My paternal grandparents were one of 12 and one of 14, born third and ninth, and even setting that aside, I’m third of six, so it’s all fallen down now 😂