I grew up in an environment that promoted a very fixed mindset. It was an era that worshipped IQ and thought that your IQ was the most important thing in determining your future. My sixth-grade teacher even seated us around the room in IQ order.
Unproductive effort is never a good thing.
One very common thing is that often very brilliant children stop working because they're praised so often that it's what they want to live as - brilliant - not as someone who ever makes mistakes. It really stunts their motivation.
We say women have made great strides: in biology, in many areas of chemistry, in many places, women are now the majority of medical students. But when I began my career, that wasn't the case. There were very strong stereotypes in biology and medicine.
We're not saying people don't need fuel for strenuous work; they just don't need it constantly. People have many more resources at hand than they might think.
The wrong kind of praise creates self-defeating behavior. The right kind motivates students to learn.