What is the self? Philosophers, theologians, and therapists offer various perspectives. I’m going to summarize some of the empirical findings related to self, beginning with Michael Tomasello’s book The Cultural Origins of Human Cognition.
There’s a 99% overlap in the DNA sequences of humans and chimpanzees. There’s just one major difference, says Tomasello, and that is the fact that human beings “identify” with conspecifics more deeply than do other primates. The young child comes to recognize herself as an “intentional agent,” with goals and strategies for attaining her desires. Soon thereafter, the child experiences herself as a “mental agent,” having thoughts and beliefs that differ from other people and from the rest of the world. The child thereby comes to recognize that others are also intentional and mental agents like herself. This is the big difference from other apes, who individually are intentional and mental agents but who don’t seem to realize that their fellow apes are too. In interacting with the physical world, humans understand cause-effect relationships at a much deeper level than do other primates. Because of the unique human ability to understand intentionality and causality, people can make tools, learn from one another, and cooperate in performing complex tasks.
At first the human infant’s developmental trajectory isn’t much different from other apes. Then comes “the nine-month revolution,” which begins the cascade of developmental achievements that definitively mark humans as unique. At six months an infant will interact with objects in the world, and she will interact one-on-one with another person. At around nine months the infant begins attending jointly to objects and people, forming a referential triangle of child, adult, and the object or event to which they share attention… In short, it is at this age that infants for the first time begin to “tune in” to the attention and behavior of adults toward outside entities.
Joint attention triggers a series of related achievements. By 12 months a child can follow the adult’s point or gaze toward an object or event — even adult chimpanzees can’t do that. By 15 months the child can direct the adult’s attention by pointing. The young child develops an awareness of intentionality in herself and in the adult, but it’s not clear whether self-awareness or other-awareness comes first. The sense of both self and other as intentional beings seems to emerge simultaneously. Tomasello elaborates on the importance of joint attention:
Human beings are designed [sic] to work in a certain kind of social environment, and without it developing youngsters (assuming some way to keep them alive) would not develop normally either socially or cognitively. That certain kind of social environment we call culture, and it is simply the species-typical and species-unique “ontogenic niche” for human development.
Through joint attention the child enters into the “habitus” of the people among whom she grows up — the kinds of living arrangements, routine activities and normal social practices that comprise the child’s “raw materials” for learning. The adult human inducts the young child into the habitus by drawing her attention to its components, demonstrating routine behaviors of the culture, and helping her perform some of the ordinary childhood activities. Tomasello believes that joint attention also facilitates the development of self-awareness during this same revolutionary developmental interval:
The idea is this. As infants begin to follow into and direct the attention of others to outside entities at nine to twelve months of age, it happens on occasion that the other person whose attention an infant is monitoring focuses on the infant herself. The infant then monitors that person’s attention to her in a way that was not possible previously… From this point on the infant’s face-to-face interactions with others — which appear on the surface to be continuous with her face-to-face interactions from early infancy — are radically transformed. She now knows she is interacting with an intentional agent who perceives her and intends things toward her. When the infant did not understand that others perceive and intend things toward an outside world, there could be no question of how they perceived and intended things toward me… By something like this same process infants at this age also become able to monitor adults’ emotional attitudes toward them as well — a kind of social referencing of others’ attitudes toward the self. This new understanding of how others feel about me opens up the possibility for the development of shyness, self-consciousness, and a sense of self-esteem. Evidence for this is the fact that within a few months after the social-cognitive revolution, infants begin showing the first signs of shyness and coyness in front of other persons and mirrors.
The empirical evidence supports the idea that a child simultaneously develops an awareness of causality, of others’ intentionality, and of the self. Joint attention in the referential triangle of child, adult, and object is the spark that sets off the developmental explosion. This developmental synchrony sets the stage for language acquisition…