[See the two UPDATES below and a newer post for information on which nursery schools were studied. These resolve some of the ambiguities discussed in this post, which I have left unedited except for the UPDATES below.]

In a long earlier post, I pointed out some problems with the Berkeley nursery school study. The more I read, the more persuaded I am that the study didn't distinguish liberals from conservatives, but rather liberals from moderates. We have to take seriously the study's admission that there were "relatively few participants tilting toward conservatism." Indeed, many of the characteristics that were attributed to the relatively conservative subjects in the study generally fit nonliberal Democrats better: e.g., the subjects were described as distrustful, worrying, anxious, and fearful, with lower intellectual capacity (and lower IQ scores), lower verbal fluency, and lower confidence. From the data and the measures used, the study probably is mostly separating liberal Democrats from nonliberal Democrats.

Support for this idea may come indirectly from a post by Michelle Malkin, who reports that it is almost certain that the nursery school that was used in the study was one run by the Berkeley Child Study Center, a school that appears to be restricted to children of Berkeley faculty and staff.

But the Block nursery school study reports:

Subjects initially (about 1969-71) were attending two different nursery schools and resided primarily in the urban areas of Berkeley and Oakland, California; they were heterogeneous with respect to social class and parents' educational level.

Perhaps I was naive, but I had assumed from this sentence in the article that two completely "different" schools were involved, perhaps one in Berkeley and one in Oakland. Now I see that in another section of the paper, the Blocks wrote:

Each child at age three was assessed by three experienced, independently functioning nursery school teachers each of whom had seen the child daily for seven months before offering their separate, well-versed evaluations. At age 4, and when in a second nursery school for seven months, each child was independently assessed again by an entirely different set of three experienced nursery school teachers functioning independently. The nursery school teachers had been selected by the nursery school head and tended to be graduate students from the University of California School of Education.

So on closer reading it appears that all of the students went from the first school to the second, which suggests (but does not establish) that both schools were part of the same organization, apparently (from Malkin's post) Berkeley's Child Study Center--which brings me to another point.

I quote the Blocks above as writing about the backgrounds of the students: "they were heterogeneous with respect to social class and parents' educational level." I don't know whether Malkin is correct that all the students at the Berkeley school were children of Berkeley staff and faculty. If they were, then the heterogeneity statement in the Blocks' statement may be highly misleading, though perhaps not literally untrue.

In the 1972 General Social Survey, only 3% of the general public had post-graduate or professional degrees. I find it hard to believe that a nursery school open only to Berkeley faculty and staff would be at all representative of the general public. (Judging from the University of Chicago's Laboratory School, whose towers I am gazing at this moment and whose classes my daughter attended from nursery school through high school, the students there were largely from families with one or more post-graduate degrees.) If the nursery school where data was collected was made up almost entirely of university kids (and I know nothing about this other than Malkin's post), then the Blocks should have informed readers how skewed in terms of education and social class the sample was. They should not have pointed readers in the opposite direction by calling the sample "heterogeneous with respect to social class and parents' educational level."

Last, if the data were collected in what was in effect one nursery school open only to the children of Berkeley faculty and staff, a liberal group if ever there was one, then it tends to support my earlier hypothesis that the sample may have so few conservatives or Republicans that the study mostly distinguishes the political left from the political center--i.e., it distinguishes the 40% of Democrats in the general public who are liberal from the other 60% of Democrats who are not.

FURTHER UPDATE: In the comments, Chris of MM pointed me to two earlier pieces by the Blocks that might have detailed information on the social class and educational backgrounds of the parents of the nursery school students. Unfortunately, they don't, but one of them confirms which nursery schools were studied and gives some additional information on the larger sample (before at least some of the attrition over time):

The children in our study were drawn from the two nursery schools constituting the Harold E. Jones Child Study Center at Berkeley . . . . One of the participating nursery schools is a university laboratory school, administered by the University of California; the second nursery school is a parent cooperative, administered by the Berkeley Public Schools. The two schools, jointly considered, attract children from heterogeneous backgrounds with regard to education, socioeconomic level, and ethnic origin. Although the sample over-represents the middle and upper-middle class, the range of socioeconomic status (SES) is wide. Sixty-one percent of the children are white, 31% are black, and the remaining 8% represent other ethnic groups, primarily Oriental and Chicano.

J.H. Block & J. Block, The role of ego-control and ego-resiliency in the organization of behavior, in W. A. Collins (Ed.), 13 The Minnesota Symposia on Child Psychology 39, at 52 [1980].

This passage confirms that the students attended schools that comprise the Berkeley Child Study Center, but makes it even less clear than it was before which parents were allowed to send students there. Would the Berkeley Public Schools run a nursery school open only to university faculty and staff children? That seems unlikely.

FURTHER, FURTHER UPDATE (Sunday, 3/26): Block responded to Malkin by email and clarified which parents were allowed to send students to the two schools, a discussion I examine here. As I speculated in the FURTHER UPDATE in the preceding paragraph, one of the two nursery schools that made up the Berkeley Child Study Center was open to the community. Indeed, Block says that university kids were barred from it.

The Comment period expired on this post (and they are impossible to turn on again), so if you want to continue commenting on either of the first two posts on this topic, you may do so at the latest post.