English: Scatter plots of phenotypic correlations (r) against genetic sharing percentages for dizygotic (DZ) twins or siblings, generated from simulations with heritabilities of 0.3, 0.5, 0.7, and 0.9 respectively. Genetic sharing percentages, typically centered around 50% for DZ twins and siblings, show natural variability (ranging from 60% to 40%, usually) due to random inheritance patterns. Linear regression lines (blue) represent heritability estimates derived solely from the DZ twin/sibling data. The estimated heritabilities (slope values) from these regression lines show the method by which DZ twin/sibling data is used in broad-sense heritability estimation. Data points are scattered with a Gaussian distribution around the 50% genetic sharing mark, with a standard deviation of 2.5%.