• Across species, social behavior is shaped by neurochemical systems: oxytocin enhances social contact [15], vasopressinergic modulation via the vomeronasal system influences social recognition [1], and serotonin/dopamine pathways emerge as social experience and stress shift neural responsiveness in crayfish and primates [13], [2], [19], [5].

• Amygdala circuits repeatedly emerge as central to affiliation and adaptive social behavior: lesions or neonatal ablations reduce affiliative responses in voles and primates, while medial amygdala disruption alters social vocalization and affiliative behavior [4], [12], [7].

• Social experience and deprivation sculpt neural processing of social information: early isolation produces lasting behavioral and neurochemical changes; learning is contextualized socially, and primate/rodent studies map perception of social acts and memory to neural substrates [6], [9], [8], [14].

• Socio-emotional functioning and psychopathology link social cognition to clinical outcomes: schizophrenia-related social skills deficits and social anhedonia trajectories anchor research in social neuroscience contexts [10], [20].