The incidence and societal impact of autism and other neurodevelopmental disorders continue to increase despite years of research. Modeling these primarily human brain disorders in animals will require investigation with diverse species. Primates exhibit a sophisticated social behavior repertoire and closer brain homology to humans, and can, therefore, function as crucial bridge species to determine neurobiological mechanisms underlying neurodevelopmental disorders; develop and test novel therapeutic approaches; and ultimately, translate basic research into safe and effective treatments. I will present our recent successes in developing and characterizing a transgenic model of a syndromic form of autism in old-world primates. Besides exhibiting shades of behaviors that broadly parallel autism, this model reinforces the conclusion that genetic deficits lead to atypical brain circuits and their functional connectivity. Based on these and other findings, in the second part of my presentation, I will describe our early effort in adapting and creating new tools for the experimental manipulation of brain circuits related to autism that span diverse aspects of sensory, cognitive and social processing, in marmosets.