Figure 2.

Partial residual plot representing the relationship between age and social content analogies accuracy after accounting for the effect of IQ. Partial residuals reflecting the predictive value of age for social content analogies accuracy were derived from a regression model in which social content analogies accuracy was regressed on both age and IQ. The trendline represents a quadratic function that was a good fit to the data, indicating a sharper increase in social content analogies accuracy in the earlier years of development.