I'm so glad you asked this question. I rarely see people question assertions like this with regards to parenting or children's behavior.
Alfie Kohn's book, "The myth of the spoiled child", spends a lot of time pointing out that evidence behind claims like this are not only deficient of data, but are claims that seem to be made continuously throughout history of the latest generation of children.
Alfie Kohn's book, "The myth of the spoiled child", spends a lot of time pointing out that evidence behind claims like this are not only deficient of data, but are claims that seem to be made continuously throughout history of the latest generation of children.