I found the book through Google Books and as I understand the argument structural changes in society were considered to precipitate subsequent changes to cultural norms or vice versa So we could expect trends in approval of CP to follow the decline in using CP attendant to the need to prepare children for the new economic realities if the hypothesis is correct the authors only state that this is likely I notice also that the graph on page 96 shows approval of CP in the US 1968 at still above 90 percent Attitudes seem to have shifted only after the 1960s