Janae and Sean are siblings who come from a family with a history of anxiety. Janae is somewhat anxious but generally takes things in stride. Sean, however, is always concerned about his health, his job, and his family even when there is no reason. Which of the following concepts proposed by Michael Rutter best explains the difference between Janae and Sean?
A. Epilogical genetics
B. Dominant and recessive traits
C. Multifactorial inheritance
D. Mitochondrial inheritance