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Why is height considered a polygenic trait?

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Fetal growth — human development Growth of the human fetus from the fourth month to the ninth month of pregnancy.

Height is considered a polygenic trait because it is not determined by a single gene, but rather by the combined influence of numerous genes and their variations—more than 12,000 in total.1

In genetics, a polygenic trait is one mediated by two or more nonallelic genes that collectively determine an inherited characteristic. Unlike traits governed by simple Mendelian inheritance, where a single gene might produce a clear-cut effect, height results from the cumulative, individually small effects of many polygenes. These genetic factors act as a blueprint for growth, influencing biological processes such as bone length and cartilage development.231

While genetics establishes an individual's potential height, the final stature is also significantly shaped by environmental factors, including nutrition, health, and hormonal regulation. Consequently, height serves as a classic example of how complex physical traits arise from the interplay between a person's genetic endowment and their environment.13