 The study of heritability has a long and rich history. Many scientific developments have led to refined techniques for estimating heritability and each of these scientific developments has been the focus of philosophical analysis. In recent years, empirical approaches toward the investigation and construction of heritability estimates have undergone great changes, especially with the introduction of GWAS, SNP chips, and SNP heritability. These recent developments are beginning to see more attention from philosophers. At the forefront of debates about SNP heritability is the issue of causation we raised above: are SNPs causal? Bourrat (forthcoming) addresses the question of whether SNPs are causal under an interventionist framework, but there is more work to be done here. Methodologically, twin and heritability and SNP heritability are estimated very differently. There is need for more philosophical analysis regarding the nature of heritability and a fine-grained perspective of the differences between twin and SNP heritability. In addition to philosophical arguments for or against causal interpretations of SNPs and heritability, scientists present their own cases, often appealing to sophisticated statistical techniques as sufficing for the identification of causal relationships in human genetics. Philosophers could profitably address such techniques—notably Mendelian randomization—with an eye for how they align with broader philosophical frameworks such as alternate accounts of causation.