I always wondered, what makes people that have a low paying job want to have so many children, I am making pretty good money but I am still having trouble keeping up with expenses (pre-school, clothes, food) with my only child, I always wondered how do those people survive with 6 kids.
Especially if you live in a good community: You hardly have to buy anything (clothing, furniture, etc), you just borrow and lend from/to neighbors and family.
Pretty much the only extra expense is food, and food in the US is not very expensive unless you eat out. And once you reach the stage where you buy in bulk prices really go down.
For example: That crib you bought for one kid - you can use it for 10 kids for the exact same price, the same is true for almost all child expenses.
Poor decision making. You'd be surprised but many don't quite know how contraception works and just believe God will take care of it. Some don't mind because they think they'll get more govt. assistance if they have another kid. There is a status perception in the community. Some think they'll fix their relationship with their partner if they have another child.
One a higher level (subconscious perhaps), you can think people who have not much going on for themselves, and see themselves basically stuck, will give up on reaching whatever goals they might have had and instead choose to procreate, hoping at least on of their children will reach those goals.
At least back in the day I heard families were large, but child mortality and mortality was high too. It was expected many would not make it, so it (again perhaps subconscious) a hedging strategy -- have more children.
Overall I'd say I spend 3-4 hours a day reading up on my field, and it took a lot of practice but now it's just a habit. I learn tons of things though,and it enables me to move from job to job and increase my pay as I implement the things I learn ( and practice on my own for a bit before trying it with a client )
Or if they do, they'll qualify for lots of assistance.