Cumulative risk and early cognitive development: a comparison of statistical risk models.

Although it is generally accepted that social risk factors predict delays in early cognitive and language development, there is less agreement about how to represent such associations statistically. Using data collected prospectively on 87 African American children during their first 4 years, this study examined 3 analytic methods for describing a child's level of social risk: (a) individual risk variables, (b) factor scores derived from those risk variables, and (c) a risk index computed by tallying the number of risk conditions present. Comparisons indicated that the individual-risk-variables approach provides better overall prediction of developmental outcomes at a particular age but is less useful in predicting developmental patterns. The risk-factor approach provides good prediction of developmental trajectories when sample sizes are moderate to large. Finally, the risk-index approach is useful for relating social risk to developmental patterns when a large number of risk variables are assessed with a small sample or when other constructs are of primary interest.