The primary distinction between heterosis and inbreeding depression is that heterosis is characterized by beneficial augmentations of phenotypic trait values in offspring of genetically distant parents. Inbreeding depression, on the other hand, is characterized by negative reductions in phenotypic trait values in the offspring of genetically related parents. As a result, heterosis results from outbreeding enhancement, whereas inbreeding depression results from inbreeding. Furthermore, heterosis is caused by increased offspring heterozygosity, whereas inbreeding depression is caused by increased offspring homozygosity.