Overestimating vs underestimating their ability has less to do with whether their estimates are correlated and more to do with the average estimation. If estim

Overestimating vs underestimating their ability has less to do with whether their estimates are correlated and more to do with the average estimation. If estimates of ability were a truly random sample with mean of 75th percentile ability, then the net effect will be vast overestimation. If they're a truly random sample with mean at 50th percentile, it will be equal. At 25th, underestimation. It's like how 90% of people estimate that they're in the top 50% of drivers by ability.