The first few months of life are important to an infant as his personality depends upon the influence of relationships. These influences are responsible for constructing a positive sense of 'attachment' in an infant. Early in the first quarter, however, the infant is unable to distinguish among individuals, and so the earliest expectations operate as generalised expectations of people. Though a parent may become attached to an infant almost as soon as the baby is born, it takes several months for the infant to feel and become securely attached, thereby identifying the parent or primary caretaker. As the infants are sociable from the moment of birth, they prefer human companionship to contact with inanimate objects, it seems that they love their parents instantly. However, until they reach 3-5 months of age, baby's sociability and attraction to people is largely indiscriminate. (Peterson, 2001, p5.22) This is evident from the scenario when a person holds a baby of 2-3 months old. It is very unusual if a baby do not cry while being in a person's custody he is unaware of. Very young infants happily accept comfort from almost anyone who holds, feeds or soothes them. The first social sign of attachment is the time they begin to smile, i.e., 6-8 weeks. By about this age infants also begin to show negative reactions to being separated from people they do not know.
Bowlby (1969) described four phases in the development of infant-parent attachments, which depicts the start of a positive relationship: the newborn phase of indiscriminate social responsiveness (months 1 to 2), the phase of discriminating sociability (2 to 7 months), "maintenance of proximity to a discriminated figure by means of locomotion as well as signals" (month 7 through the second year), and finally the phase of goal-corrected partnership (year 3 on). (Bornstein et al, 2002, p. 16)
During the first 2 months of life, human infants have some difficulty organising states of arousal and behaviour (Berg & Berg, 1979). The infant in this phase is going through various physical and mental changes, which are unpredictable; neonates appear to shift with remarkable facility from the heightened arousal manifest in the distress state to the low arousal of sleep. Only around 8-10 weeks of age, the baby's various neural components of specific states become intercoordinated psychologically. Simultaneously, state transitions become more predictable and less labile and, from this point on, longer periods of continuous time are spent in various discrete states (Lamb & Sherrod, 1981, p. 156)
By the second quarter-year of life (3 or 4 months of age), the first sign of sociability begin to emerge, as the infant starts differentiating among individuals in a systematic manner. The baby starts showing special regard for a few key people. Smiling is limited to familiar faces than to strange ones. (Peterson, 2001, p5.22) This indicates the infant is responding