Final answer:
The Italian Renaissance and the Northern Renaissance during the period from 1450 to 1550 were both influenced by Renaissance humanism.
Step-by-step explanation:
One similarity between the Italian Renaissance and the Northern Renaissance during the period from 1450 to 1550 was their influence from Renaissance humanism. Renaissance humanism, which focused on the importance of human potential and the study of classical literature and philosophy, had a significant impact on both movements. It encouraged artists, writers, and scholars to explore new ideas and perspectives, resulting in a flourishing of creativity and intellectual growth across Italy and northern Europe.