<P> Jon Miller at the Longitudinal Study of American Youth at the University of Michigan wrote that "Generation X refers to adults born between 1961 and 1981" and it "includes 84 million people". </P> <P> In their 1991 book "Generations" authors and demographers Neil Howe and William Strauss, used 1961 to 1981 for Gen X birth years . At the time it was published they wrote that there are approximately 88.5 million U.S. Gen Xers . </P> <P> The birth control pill, introduced in the early 1960s, was one contributing factor of declining birth rates seen in the late 1960s and 70s . However, increased immigration partially offset declining birth rates and contributed to making Generation X an ethnically and culturally diverse demographic cohort . </P> <P> Demographers William Strauss and Neil Howe, who authored several books on generations, including the 1993 book, 13th Gen: Abort, Retry, Ignore, Fail?, specifically on Generation X reported that Gen Xers were children at a time when society was less focused on children and more focused on adults . Gen Xers were children during a time of increasing divorce rates, with divorce rates doubling in the mid-1960s, before peaking in 1980 . Strauss and Howe described a cultural shift where the long - held societal value of staying together for the sake of the children was replaced with a societal value of parental and individual self - actualization . Strauss wrote that society "moved from what Leslie Fiedler called a 1950s - era' cult of the child' to what Landon Jones called a 1970s - era' cult of the adult' ." The Generation Map, a report from Australia's McCrindle Research Center writes of Gen X children: "their Boomer parents were the most divorced generation in Australian history". </P>

When was someone born if they are 41