The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that

Question

Quizplus · Accepted Answer

The larger the object, the longer it takes to cool down because there is more material to cool. This is similar to the cooling of a baked potato, with a larger potato taking longer to cool than a smaller one. It applies to planets as well, with larger planets retaining their interior heat for longer periods of time than smaller planets.

The Reason That Small Planets Tend to Lose Interior Heat