Chunk #113 — 5. Implications for understanding gene-brain-behavior relationships in health and disease — 5.1. Intermediate phenotypes, or “endophenotypes”
be explained by “oligogenes”, i.e. a few genes with relatively large effects. However, this assumption has been largely refuted by recent GWAS studies, as it became clear that many genes with very small effects are likely to be involved in the determination of complex human traits. Due to this complexity of pathways linking genes to behavior and small gene effects, attempts to directly associate individual genes with a complex behavioral phenotype turn out to be a formidable, if not impossible, task.
