Inhabitants of the country Orctania suffer from a much lower incidence of cancer than the inhabitants of other countries, for reasons that are generally theorized to be environmental and behavioral--the pollution-free air, stress-free and drug-free living, healthy dietary practices, and active lifestyle. Nevertheless, people from other countries who take up residence in Orctania and attempt to follow the practices of the inhabitants still have a radically higher incidence of cancer than do native Octanians.
Which of the following does