Final answer:
The research by Margaret and Harry Harlow demonstrated the importance of social comfort in infant rhesus monkeys.
Step-by-step explanation:
The research conducted by Margaret and Harry Harlow demonstrated the importance of social comfort in infant rhesus monkeys. They conducted experiments where monkeys were raised with substitute mothers made of either mesh and wire or soft terrycloth. The monkeys consistently preferred the company of the soft terrycloth substitute mother, even though it couldn't provide food, showing that social comfort was more important than food for their well-being and development.