Social interaction is ubiquitous in our daily life. It plays a vital role in both individual development and society formation. Despite significant advances in brain imaging and relevant research on social interaction during the past few decades, it remains challenging to comprehensively characterize the neural mechanisms underlying reciprocal social interaction that occurs in daily life. In this talk, Jiang will present how she tries to solve this issue using noninvasive techniques with ecological validity. She will also introduce her future research program that extends this line of research to examine how humans develop and improve social interaction abilities.