Theory 96/Selection & Bias/Human genetics
Ascertainment Distorts Heritability
The claim
Heritability estimates from ascertained samples are biased in proportion to the ratio of ascertainment strength to trait heritability.
01Mechanism
Selecting on a phenotype enriches variants associated with it, inflating the estimated genetic contribution relative to the population.
02Prediction
Estimates should fall in population-based samples.
03Refutation
Equal estimates across sampling schemes would remove the bias.