Joseph and Gabriel:
Once, when I was in teacher training, I invited a friend out to do friend stuff. It was a weekend, sometime near the end of the term. She told me she couldn’t hang out because she had a stack of papers almost 13 inches high to grade.
My oldest son, Joseph, is very extroverted. Gabriel, his younger brother by two years, is the opposite. On any aptitude or intelligence test, I would bet that the older one scores higher.