'and that similarly children in families of 5 or more are more likely to be disordered because of the difficulty in providing individual attention'
What rubbish, would like to see what studies they based those findings on!!
I come from a family of six, ten year age gap between first two, then 18 months or two years between the next three, then six years between the last two. We are now aged 37, 27, 25, 24, 22 and 15.
We always had quality time with our parents, they had this many because they like children and being parents. All my siblings are now 'normal' stable adults and we are a very close family.
Surely people don't think quality time has to involve one to one time?!?! I had quality time with my family, in all sorts of different combinations, and still do. There is certainly never a shortage of people giving you attention, I think my 15 yr old brother in particular gets huge amounts of quality time and attention, he doesn't just have two adults who care about him and love him, he has seven!
It's great now for my ds too, with so many doting aunts and uncles!
No one family type is ideal or better than any other, all sorts of combinations work really well. I think a lot of it comes down to the parents.