Final answer:
The statement 'Morality is by constraint' is irrelevant to infancy, where the focus is on sensorimotor development and the attainment of cognitive milestones like object permanence. During this period, infants explore the environment and form attachments which are crucial for their later emotional development.
Step-by-step explanation:
During the first two years of life, an infant's stage is commonly referred to as the sensorimotor stage, coined by developmental psychologist Jean Piaget. This period is marked by a profound growth in sensory experiences and motor skills, guiding infants' understanding of the world. One significant cognitive milestone during this stage is the development of object permanence, which typically occurs around 8 months old. This is the understanding that objects continue to exist even when they're not visible.
With respect to the question about the relevancy of certain statements to this stage of development, the statement 'Morality is by constraint' is not directly related to infancy. Morality related to constraints typically refers to concepts that are more applicable to later developmental stages, such as the concrete operational or formal operational stages, where children develop the ability to understand rules and regulations imposed by authority.
Infants also start to show initiative in exploring the world and show preferences for certain foods, toys, and people. One of the key features of infancy is the formation of attachment to caregivers, which lays the foundation for their emotional development.