Chilfree is a term used to describe individuals who neither have nor desire to have children. An alternative description is "childless by choice". The choice not to procreate has only been popular since the development of reliable birth control and therefore was not commonly seen before the 1960s. Additionally, such an option is rarely seen in non-industrialized countries. Childfree groups began to form in the 1970s, most notable among them The National Organization for Non-Parents and No Kidding!. There have been a significant number of books written about the childfree, although quantitative academic research on this group is just now emerging.