Harris uses the fairy tale of Cinderella as an analogy for how people can develop two personalities in different social contexts. Cinderella was quiet and obedient at home in order to avoid the cruelty of her stepmother and stepsisters. However, Harris imagines she behaved differently outside the home, allowing her to befriend her fairy godmother and attract the prince. She argues that, like Cinderella, it is normal for people to maintain different personalities in different social contexts. She cites research that shows that even infants and toddlers behave differently in different settings, such as at home and daycare. People create memories based on their experiences in different settings, but they do not seem to readily apply lessons learned in one setting to their experiences in another. Evidence suggests people innately know their knowledge is not always transferable and can change their behavior to adapt to a new situation. For example, a dominant sibling may act submissively with peers. Even if some behaviors are long-lasting, such as sibling rivalry, this does not mean this relationship sets a life-long pattern.

Language is another way in which people create different selves in different settings. Children are born wired to learn language, and with an innate desire to communicate with others.