Although the primary purpose of this essay has been to argue that the virtually exclusive focus on adverse environmental conditions and psychopathology in psychiatric genetic research risks mischaracterizing individuals who are more susceptible than others to the negative consequences of adversity and to the benefits of environmental support and enrichment as being exclusively the former—that is, genetically vulnerable—it would be a mistake to view these orientations as mutually exclusive. Indeed, thinking about plasticity and vulnerability together raises the following three interrelated questions: Are there some polymorphisms that make some individuals more responsive than others to supportive and adverse environments, just as a differential-susceptibility framework presupposes? Are there some polymorphisms that only cause some individuals to be more susceptible than others to adversity, just as a diathesis–stress/genetic-vulnerability framework presupposes? And are there still other polymorphisms that only make individuals more susceptible than others to enriching environmental conditions? Of note, with regard to the last possibility is that, although the English language has terms to characterize those highly susceptible to both positive and negative conditions (that is, plastic/malleable) and highly susceptible to
