Psychological Needs of Various Groups in Health and Sickness: Infancy Stage Infancy (from birth to 1 year) is a critical stage of psychological and emotional development. The psychological needs of an infant vary based on health status (healthy or sick) and are primarily centered around security, attachment, stimulation, and comfort. 1. Psychological Needs of a Healthy Infant A. Basic Trust and Security (Erikson’s Trust vs. Mistrust Stage) B. Emotional Bonding