Why do we use the sample standard deviation for smaller data sets, such as those with less than 20 samples?

Question

Quizplus · Accepted Answer

With smaller sample sets, the standard deviation of the parent population is often underestimated. This is because the sample tends to be more homogeneous, which leads to a smaller standard deviation. Using the sample standard deviation in these cases can give a more accurate representation of the variability within the sample.

Why Do We Use the Sample Standard Deviation for Smaller