Final answer:
Heritability estimates can be incorrect due to small sample sizes, which may not represent genetic variability accurately, or due to statistical errors such as Type I or II errors. These inaccuracies are compounded by biases and environmental influences not accounted for within the study.
Step-by-step explanation:
Heritability estimates might be wrong in two instances: first, when sample sizes are too small to accurately reflect the true variability within the population, and second, when there are errors stemming from bias or chance. In the case of studies with small sample sizes, such as those involving family genetics, the randomness of allele distribution may significantly alter the expected outcomes (e.g., the expected 3:1 phenotypic ratio in Mendelian inheritance might be skewed in small human families, as opposed to Mendel's large sample of pea plants). Another instance of inaccuracy is when statistical studies suffer from either Type I or Type II errors, where researchers might wrongly accept or reject a hypothesis due to chance variation within the sample. Furthermore, heritability can be impacted by environmental factors that aren't considered in the estimates, such as when polling companies produce incorrect predictions due to poor survey design or respondents not behaving in predicted manners.