<prompt> Which of the following is not a central characteristic of childhood autism?Impaired social interactionImpaired communicationRestricted, repetitive behaviourCallous and unemotional traits  <response>: Callous and unemotional traits CU are distinguished by a persistent pattern of behavior that reflects a disregard for others, and also a lack of empathy and generally deficient affect seen in conduct disorder and antisocial personality disorder. Reference: GHAI Essential pediatrics, 8th edition 