We investigate the neural and genetic mechanisms underlying social behaviors across the lifespan. Using the tiny, transparent Danionella cerebrum as a model system, we explore how brain circuits develop, adapt, and function in social contexts. Our research integrates functional imaging, molecular profiling, and behavioral assays to uncover how genetic and environmental factors shape social interactions. By combining developmental, neurogenetic, and systems neuroscience approaches, we aim to advance our understanding of the 'social brain' that leads to collective behaviors and their disruptions in neurodevelopmental disorders.