Prior to 1970, California labor laws prevented women from working more than eight hours a day or 40 hours a week. Why? There was a faulty assumption on the part of lawmakers that the “weaker sex” needed protection from the rigors of overtime work.
An assumption is a belief based on little or no evidence. Assumptions lead to stereotypes. This stereotype about women was so generally accepted, it took years of feminist consciousness-raising to overcome.
Though of lesser social impact, perhaps, the same thinking is today falsely categorizing a different group of workers. This time, false assumptions are stereotyping generations, most egregiously, the Millennial generation.