Although I haven't really dived into the literature on the effects of day care, it seems clear that the major studies look at the kids' cognitive and emotional development as the outcome variables.*
That is too narrow of a focus, since socialization does not merely mean "gets along well with generalized/abstract others," but has become integrated into a community of his particular peers and elders. We could go further to include becoming integrated into a particular neighborhood or region -- a particular environment that he feels rooted in.
An earlier post about the lasting effects of divorce on children made the point that social scientists ought to move beyond strictly individual traits (the best example being intelligence) to include social relationships at varying levels above the individual (like integration within a community).
How can this approach be applied to the divisive topic of day care for children?
I think it says a lot that no one has many fond memories of day care, in contrast to grade school. School is not a glorified form of babysitting, as they make some kind of effort to enculturate the students -- both works of formal culture and informal folkways -- and to get them to feel and act as part of a cohesive group of youngsters.
Day care administrators and workers hold no pretense about the children interacting with each other outside of the center, or inside for that matter. No effort is made to make sure the kids know each other's names. They don't expect kids to remember the "counselors" either. They operate more like a pet hotel, in keeping with parents nowadays viewing and treating their children as pets. The social atmosphere is atomized and high-density -- how else are normal human beings going to come out on the other side?
I have a very good memory, and went through several years of day care. Yet I don't remember anyone's name, whether a student's or a worker's. I didn't meet any of the students outside of center hours.
I remember exactly two faces: that one girl who invited me under the table during naptime for a game of "I'll show you mine if you show me yours," and one of the workers who gave me a warm hug during a field trip. I didn't need it at the moment, it was more of a maternal "just cuz" sort of gesture. That stuck out in my mind because typically the day care workers don't see you as an emotional creature -- more like something that has to be distracted ("entertained") and ordered around until it's claimed by its owner.
I don't recall many experiences other than those two above, although I do remember more about the physical environment (the indoor rooms and the playground area outside). Can't say I have any fondness for those places, though.
I never wanted to go to day care, and always felt that pick-up time was like being rescued.
In all of these ways, day care was the opposite of school. Most people like going to school, however much they may bitch about certain aspects of it. There's a certain anticipation before each school day starts, and definitely by the end of summer when you can't wait any longer. It was not uncommon to feel like hanging around school after the day was formally over, and getting picked up by your folks did not feel like they were rescuing you.
We can't begin to count all of the major and minor experiences we remember taking place in and around school, and beyond its walls in the company of our friends from school. We remember all sorts of gross and fine details about the physical environment at school, and generally have fond memories of those places.
We remember scores of names and faces, both from our peers and our teachers, and have yearbooks just to make sure. And our teachers cared more for us, whether they were gentle or stern, than day care workers. We made friends with our schoolmates, our parents kept in touch with other parents -- and teachers -- and there was a phone directory to facilitate these interactions outside of the school setting.
Not to mention the teams, mascots, school colors, and so on and so forth that gave us a more palpable group identity.
This stark contrast between schools and day care centers should be emphasized by conservatives. Jonathan Haidt's work on variety in moral frameworks shows that cons are more sensitive to one based on valuing and strengthening the in-group, whereas libs are either numb to the sense of belonging, or are actively hostile to it. (The former are standard liberals, the latter are more like libertarians.)
If one of the goals of socialization is to give youngsters a place to fit in within a larger group, day care begins to look way worse than it already did, a place that had left even liberals nervous. It's atomized, each kid is looking out for himself, and only the Dickensian supervisors keep that from unfolding. Prison, pet hotel -- take your pick of metaphor, but none of them bring to mind a cohesive in-group.
Day care would also make for a good place to find common ground with the minority of liberals who have half a lick of common sense. It's difficult even for rationalizers to make day care look like anything other than a way for parents (especially mothers) to pursue greater levels of status-striving, unfettered by having to pay any attention to their kids' immediate needs, and during such a sensitive and impressionable period in the child's life.
Ideally, we wouldn't have to subsidize mothers with "maternity leave" payments to stay home with their young children. Status-striving would ideally be at a low enough level that it wouldn't occur to mothers that they'd need to be bribed into doing so. But I wouldn't be above granting an increase in maternity leave in the short-term, as long as it had a phasing-out built into it. We have to get there from here, and mothers are still pretty careerist.
That would also be a nice way to start diverting public funds from the Silents and Boomers, who have been absorbing them way more than any other group in history, for decades now, and direct more of it toward the financially unstable generations after them, who will also be faced with paying down the massive debts of their "boo taxes" elders.
Regardless of how it works out in policy, the movement against day care seems like a no-brainer for folks who are sick of the morally lax society that we have become.
* Not surprisingly, kids who spend a lot of time in day care have greater emotional problems that last into adolescence (and who knows, perhaps longer). Perhaps those are due to selection bias, whereby troubled kids are more likely to get dumped for long hours in day care by parents who'd rather not deal with them directly.
Whatever the cause, it's still a fact that sending your kid to day care amounts to giving them a potential peer group that is more defiant, argumentative, and acting-out than the group he'd receive from socializing around the neighborhood while spending the day at and around his own home.
Then again, most psychological liberals don't see anything beyond the individual, such as quality of peer group. They're only concerned with how day care may or may not help in making the kid smarter and better behaved.