Growing genetic evidence including results of genome-wide association studies and whole-genome sequencing is still perplexing scientists in the fields of human complex traits and compels them to reconsider the relationship between autism spectrum disorder (ASD) and schizophrenia. The developmental trajectory of schizophrenia may be characterized by difficulties in “theory of mind” tasks, poor insight or imagination, low empathy level, weak executive function, failure in social judgments, delayed language development, movement mannerisms, motoric rituals, strong preoccupation with unusual objects, bizarre habits, and high intelligence. Most of these characteristics are associated with the standard criteria for ASD and all of them are core domains or endophenotypes of ASD. The diagnosed ASD cases, which were found in individuals with schizophrenia, have a significant tendency to be highfunctioning and to have atypical age of ASD manifestation. Episodic features including reality distortion, which can be seen in individual with ASD, may be associated with hyperarousal conditions with cognitive hypersensitivity, misattribution of negative experiences, and the perceptual thinking style. Together with the emerging new genetic concepts concerning human behavioral complex traits, the results and constructions of these recent studies may further warrant that reconsideration of the relationship between ASD and psychotic conditions is necessary. In addition, the possibility that psychotic conditions are the secondary derivative states in individuals with ASD or in individuals with subclinical ASD components should be constructively examined.