Final answer:
During infancy, primary emotions such as trust, joy, sadness, and stranger anxiety develop through interactions with caregivers and psychosocial development. By about 18 months, toddlers begin self-awareness, recognizing themselves in a mirror. Responsive caregiving promotes trust and a view of the world as safe, while unresponsive care can lead to mistrust and fear.
Step-by-step explanation:
During infancy, which is the period of most rapid growth after birth, infants develop a range of abilities, including those related to emotions. According to Erikson, the primary task of infancy is trust versus mistrust. Responsive and sensitive caregivers help an infant develop a sense of trust and view the world as a safe, predictable place. On the other hand, unresponsive caregivers can lead to feelings of anxiety, fear, and mistrust in infants.
Babies display primary emotions such as joy and sadness quite early in life. For instance, toddlers can exhibit extreme happiness one moment and extreme sadness the next, as they cycle through emotions quickly. Psychosocial development, which occurs as children form relationships and manage feelings, is marked by the ability to form healthy attachments, a significant milestone during infancy.
Self-awareness, a part of this emotional development, begins when toddlers recognize themselves in a mirror, a discovery that usually occurs by about 18 months old. Malatesta and Haviland's research in 1982 on the socialization of emotion expression in infancy suggests that infants learn display rules for emotions from their caregivers.
Furthermore, Piaget's theory indicates that alongside the development of object permanence, infants also begin to exhibit stranger anxiety, a primary emotion that demonstrates a fear of unfamiliar people. This occurs when a child cannot assimilate the stranger into an existing schema.