Effects of PCBs on adolescent affiliative and sociability behavior with a same-sex and age conspecific. Frequency modulated (FM) or flat ultrasonic vocalization (USV) production (A, B); play behaviors (C, D); and time spent with, and latency to reach, the stimulus animal in Stage 1 of the sociability test (E, F) are shown. Bars are mean ± SEM, with dots indicating individual data points. Within-sex main effects (ME) of, or interactions between, prenatal (Pre) or juvenile (Juv) exposure are described in each subtitle, with specific group differences indicated by *, p < 0.05 or **, p < 0.01.