Final answer:
Taller individuals often have a higher center of gravity, allowing smaller displacements to move it outside the base of support, leading to less stability compared to shorter people. Additionally, children and those with certain medical conditions may have different stabilities due to the center of gravity's location and bone structure.
Step-by-step explanation:
The reason why taller people are generally considered less stable than shorter ones has to do with human physiology and physics. The center of gravity (cg) of an adult is located above the hip joints and lies between the feet, which are not very long. Essentially, a person is in a kind of stable equilibrium in relation to sideways displacements; however, because taller individuals have a higher center of gravity, it takes smaller displacements to move it outside the base of support, causing instability. When the feet are spread apart, stability improves as the base of support widens. For those with abnormally long bones, due to various medical conditions, this could mean greater instability. Furthermore, growing children have a center of gravity that is higher, which makes it more difficult for them to learn to walk. While this is simplified, it covers the essential factors that can influence a person's stability based on their height.