Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The solid line between mother and child represents a tie that is always present, as in this study because children were recruited through their mother; dashed lines represent ties that may or may not exist.
