Bad eyes and big nose? Blame your parents

Scimex: A large Australian-led study has pooled genetic data from a collection of twin studies, in order to determine the extent of heritable traits - the features that are passed down in families - in humans. They tested 17,804 traits in humans, and found that some of the most heritable included those that are associated with the eyes, ears, nose, throat, skin, and bones, whereas some of the least heritable were in areas such as reproduction and social values.

Despite a century of research on complex traits in humans, the relative importance and specific nature of the influences of genes and environment on human traits remain controversial. We report a meta-analysis of twin correlations and reported variance components for 17,804 traits from 2,748 publications including 14,558,903 partly dependent twin pairs, virtually all published twin studies of complex traits. Estimates of heritability cluster strongly within functional domains, and across all traits the reported heritability is 49%. For a majority (69%) of traits, the observed twin correlations are consistent with a simple and parsimonious model where twin resemblance is solely due to additive genetic variation. The data are inconsistent with substantial influences from shared environment or non-additive genetic variation. This study provides the most comprehensive analysis of the causes of individual differences in human traits thus far and will guide future gene-mapping efforts. All the results can be visualized using the MaTCH webtool.