Do short people build muscle faster than taller people? Technically no, but smaller amounts of muscle does show up more apparently on shorter people. If a short person and a tall person do the same workout over time, they will gain around the same amount of muscle, but the muscle will be distributed across more surface area on the taller person, causing the person to look leaner than the shorter person. Over time, this will even out naturally as both parties will plateau at a larger muscle mass. It is not easier for short people to gain muscle.
Short people have better leverage with their smaller limbs, technically making it easier to lift higher numbers compared to taller people. Their maximum limb extension being smaller also means that they have less distance from their starting point to the goal in their lift, meaning that the lift will require less effort. That being said, this means that the workout is less physically demanding. This causes less muscle growth from the same workout compared to a taller person.
Despite all of the technicalities above, genetics play the biggest role in the speed of muscular growth as well as maximum size and plateaus. Genetics are incredibly complicated, so the best way to determine how your genetics will play a role in your muscle development is to look at your family members’ builds. Do they have an easy time gaining muscle? Do they maintain muscle for longer through periods of not working out? Are they naturally larger-bodied, or are they lean? What is their metabolism like? All of these are keys to how genetics will affect your overall muscle growth. Genes can affect not only muscle growth speed, but also muscle retention. This plays a much larger role than height does when it comes to building muscle.
In a perfect test environment where a taller person and a shorter person have similar genetics, the shorter person will appear to have more muscle, but the taller person would technically be building muscle faster. This is not applicable in the real world, however. A combination of all of these factors will determine your muscle growth rate. In conclusion, it is not easier for short people to gain muscle.