In utero and during the first 5 years of life, boys face unique risks as a result of neurobiological and environmental factors. This introductory article to the Special Issue describes the background of this gender‐specific inquiry and outlines some of those risks, drawing attention to the areas that will be covered in depth in the following contributions. We also describe the basis of this inquiry as the link between early life and the subsequent difficulties that adolescent boys and many young men face, and pay particular attention to the circumstances of young men of color and to the growing knowledge about the contributions of fathers to boys’ development.