According to a study published in the US National Library of Medicine for the National Institute of Health (Draper Fund Rep. 1982 Dec;(11):19-22.):
Abstract:
"For some time now there has been a multidisciplinary interest in the effects of family size on children's development and on their overall life outcomes. In general, available evidence indicates that children from small families tend to accrue advantages in many developmental areas, while children from larger families are, as a group, relatively disadvantaged. Care needs to be taken when drawing conclusions from correlational research, yet there is growing evidence that even when the social class of families is accounted for, children from smaller families fare better on many measures of development than those from large families. 1 of the best documented research findings is that children from smaller families perform better on tests of intellectual ability than children from large families. Efforts to understand why family size should affect intellectual performance have intensified in recent years. Many explanations have been offered, but the explanation termed the "confluence model" has attracted the most interest and controversy. According to this model, a child's intellectual development is a function of the intellectual environment provided by the family. That environment is conceptualized as the average of absolute intelligence of all family members. A child is born with an absolute intelligence of zero. The arrival of each additional child has the effect of lowering the family's intellectual environment. Thus, children from larger families grow up in a less enriched environment and tend to perform less well on measures of ability. A 2nd component of the confluence model is necessary to explain the phenomenon that "only" children fail to perform as well as might be expected on intelligence tests. According to the confluence model, the only child discontinuity results from the absence of an opportunity to tutor younger siblings. Available evidence indicates that family size exerts an effect on educational and occupational achievement over and above its effect on ability. A multidisciplinary explanation for the findings on family size suggests that family resources become "diluted" as family size increases and the result is the various developmental deficits reported by researchers. In sum, there is substantial documentation indicating that children from small families have a better developmental prognosis than children with many siblings. In the aggregate, these effects could have a substantial impact on the quality of a country's citizenry."
Another reason to "care" what the Duggars do and how it can affect others as citizens. It can be dangerous to think that because the Duggars seem to have done it well it is a healthy lifestyle that would be good for society overall. There is a matter of personal choice, but there is also the matter of being a responsible member of society as a whole.
Have the Duggars used the term "quiverfull" to describe their belief system? I thought that Michelle just had difficulty with one of her pregancies and afterwards swore to honor each child her "God" decided to give her. The Quiverfull movement is a religious movement that advocates having a huge amount of children with the aim of overtaking society with members from their own personal religious beliefs. I have a very brief knowledge of the Duggars, but I am not so trusting as to believe that what goes on in front of the cameras is what goes on behind the cameras. I thought I heard somewhere that one of their neighbors reported that when the cameras are not on, the older children keep the younger children on a large blanket, and they are trained to not go off of the blanket by being hit with a switch when they do. This is why they are able to have such a large amount of children as the older children ensure that they younger children stay on the blanket. Granted, that was totally undocumented "neighbor" information (the neighbor wasn't even identified), so I put no stock in that statement either, but I do know that kind of parenting is advocated and practiced in the Quiverfull movement.