Verbal communication, nonverbal communication, and private speech in lower and middle socioeconomic status preschool children.
Three types of communication--verbal, nonverbal, and private speech--were investigated in 4- and 5-year-old children. Multiple analyses of variance (MANOVAs) without IQ controlled and multiple analyses of covariance (MANCOVAs) with IQ as a covariate were computed and followed by ANOVAs and ANCOVAs to determine the effects of sex, age, and socioeconomic status (SES) on each of these types of communication. The ANOVAs and the ANCOVAs yielded the same conclusions. Results indicated that age and SES, but not sex, influence the use of the three communication types. From age 4 to age 5, private speech decreased for middle SES children and remained the same for lower SES children. Although lower SES children had more nonverbal communication at both age levels than middle SES children, nonverbal communication decreased for middle SES children and increased for lower SES children between the ages of 4 and 5 years. Both lower and middle SES groups increased in verbal communication between the two ages. The middle SES 4-year-olds used more verbal communication than their lower SES counterparts, and the difference was maintained at age 5. Although IQ is related to verbal communication, statistically controlling for the effects of IQ did not change the conclusions.