Additive genetic effects refer to the contribution of specific genes to a certain trait or characteristic. This is distinct from genetic interactions or environmental factors that may also influence the trait in question. Other terms that can be used as synonyms for additive genetic effects include genetic variance, heritability, genetic influence, and genetic contribution. These terms all refer to the degree to which a specific trait is influenced by an individual's genetic makeup. By understanding the role of additive genetic effects in various traits, researchers can better understand the underlying genetic mechanisms that influence a wide range of biological processes, from disease susceptibility to physical performance.