Natural selection (Darwin’s evolution) drives animals toward faster, stronger, and more lethal. Greater specimens act freely, while lesser creatures scrabble in the shadow of death. Imagination changes that picture: lesser creatures still submit, but may observe and plan to turn the tables on their oppressors.

In society, the immediate merits of action and planning are obscured by ritual, rules and rights. The Greek philosophers admired the tyrant – a man capable of driving an entire city toward a common goal. To temper his excesses, the Fathers of the Catholic Church invented the feudal hierarchy: ownership was ceded to the tyrant, but the Church agreed to manage property (including vassals and serfs) only if the tyrant defended the commandments (foremost being “thou shalt not murder”). History tells us that to escape these constraints, the kings established secular universities. It was then left to their vassals to organize parliamentary procedures to reign in the tyrant.

In “Quiet”, Susan Cain dissects the status in America society of the balance between action and planning. As offered by Jung, the preferences carry the labels “extroverted” (for those that prefer action) and “introverted” (for those that plan).

The struggle is intensified by the tendency of individuals to prefer one or the other as a competitive strategy. From the title, you might expect that Cain is partial to introversion, and indeed she uses personal illustrations as she catalogs the costs of America’s deference to extroversion. The projection of ego has been designed into education, work, and social interactions. This allows the aggressive extrovert to monitor and disrupt planning. Cain implies that this is undermining the creativity that is the foundation of vibrant economies. Yet while Cain is sympathetic to the plight of introverts in this culture, she draws a balanced picture of the two types, concluding that they form natural partnerships.

Our personal preference is fundamental to the personality, evident in infancy and persisting through adulthood. The origin of the preference is obscure; Cain spends several chapters surveying the studies that explored the relative impacts of nature (genetics) and nurture (life experience). I concluded that there seems to be a missing factor – perhaps the biochemical milieu during gestation and infancy?

But the studies do illuminate the behaviors that distinguish the extrovert from the introvert. Planning requires information, and thus introverts are “sensitive.” The introvert in unfamiliar surroundings is hypervigilant to the point of exhaustion. This makes them shy of the public performances dominated by extroverts. Conversely, extroverts commit prematurely to goals, a tendency that can drive them to expensive mistakes (Cain references disastrous corporate mergers).

Cain prescribes two paths for strengthening the introvert’s hand. The first is the power of purpose in projecting introverts into public dialog. Cain uses her personal history as one illustration. As a legal advisor, she was terrified of public speaking. While still anxious before presentations, she is stimulated by the worthiness of her mission (coaching introverts to greater influence). Her first recommendation, then, is that introverts seek work that they value.

Using Franklin and Eleanor Roosevelt as examples, Cain’s second path illuminates the power of collaboration. The illustrations in this last section of the book become a little testy, particular in vignettes of group work in school that tend to bullying by the extrovert. But she concludes with vignettes that emphasize the value of allowing each party to lead in their domain of excellence.

Cain’s study is a valuable read for the hypnotherapist, but also sends up a warning flag for the Kappasinian practitioner. Kappas elaborated the categories as “Emotional” and “Physical” types of suggestibility and sexuality. Those distinctions are a powerful aid in therapy, but Cain’s exploration of introversion and extroversion is proof that psychologists are working toward those same insights. While Kappas’ theory is more pervasive – covering learning, communication, intimacy, and child rearing – it’s only a matter of time before those aspects are integrated under Jung’s terminology.