I found this interesting and the paper it discusses children's conception of intelligence.

The abstract to the article

Two studies explored the role of implicit theories of intelligence in adolescents' mathematics achievement. In Study 1 with 373 7th graders, the belief that intelligence is malleable (incremental theory) predicted an upward trajectory in grades over the two years of junior high school, while a belief that intelligence is fixed (entity theory) predicted a flat trajectory. A mediational model including learning goals, positive beliefs about effort, and causal attributions and strategies was tested. In Study 2, an intervention teaching an incremental theory to 7th graders (N=48) promoted positive change in classroom motivation, compared with a control group (N=43). Simultaneously, students in the control group displayed a continuing downward trajectory in grades, while this decline was reversed for students in the experimental group.

People on lesswrong commonly talk as if intelligence is a thing we can put a number too, which implies a fixed trait. Yet that is counter productive in children. Is this another example of a useful lie? I feel that this issue is at the core of some of the arguments I have had over the years.