“Although nurture does not change our basic personality type, it can in some ways cloud or impair our ability to accurately perceive our true type. Imagine, for instance, an extravert raised as an only child in a rural area, with no one but her parents to talk to. Such a child would seem far more likely to develop her introverted capacities than one raised with multiple siblings, which may in turn compromise her ability to grasp her true status as an extravert.”