Page 178: Children differ greatly in the age a t which specific attachment occurs. Among the 60 babies in the Schaffer and Emerson study, 1 showed specific attachment at 22 weeks, whereas 2 did not display it until after their first birthdays (Van IJzendoorn & Sagi, 1999). Cross-cultural differences also play a part in this development. Mary Ainsworth found that infants in Uganda show specific attachment at about 6 months of age—a month or so earlier than the Scottish infants studied by Schaffer and Emerson (1964). Similarly, it was found that separation protest occurred earlier among infants in Guatemala than among those in the United States (Lester et al., 1974). Researchers attribute the precocity of the Ugandan and Guatemalan infants to cultural factors. Ugandan infants spend most of their time in close physical contact with their mothers (they are carried about on their mother's back), and they are rarely separated from her. Generally, American infants are placed in their own rooms shortly after birth. Such separation is virtually unknown in Guatemala, where most rural families live in a one-room rancho. Other research findings with a small sample of Colombian mothers and infants support A insworth's concepts of attachment theory (Posada et al., 2004). Schaffer (1971, 1996) suggests that the onset of separation protest is directly related to a child's level ofobject permanence. Social attachment depend s on the ability of infants to differentiate between their mother and strangers and on their ability to recognize that their mother continues to exist even when she is not visible. In terms of Piaget's cognitive theory, outlined in Chapter 5, these abilities do not appear until late in the sensorimotor stage, Indeed, Silvia M. Bell (197D) finds that in some instances the concept ofperson permanence—the notion that an individual exists independently of immediate visibility—might appear in a child before the concept ofobject permanence. Studies by other researchers also confirm that protests ove r parental departures are related to a child's level of cognitive development (Kagan, 1997; Klaus & Klaus, 1998). How Do Attachments Form?Psychologists have advanced two explanations of the origins or determinants of attachment, one based on an ethological perspective and the other on a learning perspective. Psychoanalytically oriented ethologist John Bowlby ( 1969, 1988) said that attachment behaviours have biological underpinnings that can be best understood from a Darwinian evolution- ary perspective. For the human species to s urvive despite an extended period of infant immaturity and vulnerability, both mothers and infants are endowed with innate tendencies to be close to each other. This reciprocal bonding functioned to prote ct the infant from predators when humans lived in small nomadic groups (Bowlby, 1969, 1988). According to Bowlby, human infants are biologically pre-adapted with a number ofbehavioural systems ready to be activated by appropriate "elicitors" or "releasers" within the environment. Close physical contact—especially hold-ing, caressing, and rocking—often soothes and quiets a distressed, fussing infant. Indeed, an infant's crying literally compels attention from a caregiver, and smiles accomplish much the same end (Grossman, Grossman, & Kindler, 2005).
