Polygenic traits are traits determined by the combined effect of more than one pair of genes. Human stature is an example of this trait. The size of all body parts from head to foot combined determines height. The size of each individual body part are determined by numerous genes.
Although you don't necessarily have to major in interior design, a bachelor's degree or higher in the discipline provides the best foundation for a career, according to the Foundation for Interior Design Education and Research.
If you need to work and study at the same time, consider an online degree program in interior design. You'll be able to study on your own time and immediately apply what you learn to your current job, allowing you to rise faster through the ranks. An interior design degree opens up many career paths to you.