Socialization theory has focused on enculturating new employees such that they develop pride in their new organization and internalize its values. We draw on authenticity research to theorize that the initial stage of socialization leads to more effective employment relationships when it instead primarily encourages newcomers to express their personal identities. In a field experiment carried out in a large business process outsourcing company in India, we found that initial socialization focused on personal identity (emphasizing newcomers’ authentic best selves) led to greater customer satisfaction and employee retention after six months than socialization that focused on organizational identity (emphasizing the pride to be gained from organizational affiliation) or the organization’s traditional approach, which focused primarily on skills training. To confirm causation and explore the mechanisms underlying the effects, we replicated the results in a laboratory experiment in a U.S. university. We found that individuals working temporarily as part of a research team were more engaged and satisfied with their work, performed their tasks more effectively, and were less likely to quit when initial socialization focused on personal identity rather than on organizational identity or a control condition. In addition, authentic self-expression mediated these relationships. We call for a new direction in socialization theory that examines how both organizations and employees can benefit by emphasizing newcomers’ authentic best selves.