FIGURE 4.

Principal component analysis (PCA). The two clusters containing ADOS RRB “high” and “low” are in a perfect symmetry. The cluster around ADOS RRB “high” indicates the following hierarchy: “ADOS Module 1,” “Stationary low,” “Object Manipulation low,” “Locomotion low,” “Gross MQ low,” and “Non-verbal IQ low,” and in the same way the cluster around ADOS RRB “low” shows the following hierarchy: “ADOS Module 2” “Stationary high,” “Object Manipulation high,” “Locomotion high,” “Gross MQ high,” and “Non-verbal IQ high.”