Lack of empathy is a hallmark of social impairments in individuals with autism spectrum disorder (ASD) and psychopathy with high callous-unemotional traits (CUT). However, the available empirical evidence to empathic deficits is, at best, contradictory. Given the complexity of the phenomenological experience of empathy, we investigate the neurobiological underpinnings by conceptualizing empathy as a construct that comprises sensorimotor resonance, emotional and cognitive components. Adolescents with ASD, high CUT, and typically developing controls received the quantitative sensory testing of pressure pain thresholds (PPT) along with fMRI scanning and EEG/ERP recording to empathy-eliciting stimuli depicting physical bodily injuries. Results indicate that subjects with ASD subjects had lower PPT but CUT had higher PPT than controls. When perceiving other’s pain, subjects with ASD showed frontal N2 and LPP, which were diminished in those with HCU. In this case, the anterior insular activations was reduced in ASD but heightened in psychopathy. When perceived the agency, the ASD diminished LPP but the HCU retained LPP. Both ASD and HCU groups had normal sensorimotor resonance, indicative of typical sensorimotor resonance of pain empathy. The findings provide the evidence to empathy imbalance hypothesis, suggesting that, autism and psychopathy as diametrically opposed disorders with empathy imbalance.