Final answer:
Offering round-the-clock nursery care for all infants would be the least effective practice in promoting bonding and attachment as it limits parental interaction.
Step-by-step explanation:
The practice that would be least effective in promoting bonding and attachment is offering round-the-clock nursery care for all infants.
This practice may actually hinder bonding because it separates infants from their parents, reducing opportunities for close interactions and physical touch that are crucial for bonding.
Research by Harry Harlow and Mary Ainsworth has shown the significance of early social contact and the comfort of the caregiver for the healthy psychosocial development of infants.
On the contrary, practices such as allowing unlimited visiting hours on maternity units, promoting rooming-in, and encouraging infant contact immediately after birth are known to facilitate bonding and attachment.