Answer:
The New England colonies were ethnically homogeneous, heavily skewing toward anglo-saxon, and protestant.
The Middle Colonies were ethnically more diverse, because they promoted a greater degree of religious freedom. In these colonies, there were quakers, catholics, puritans, anglicans, calvinists, and some non-anglo immigrants, especially Germans and Dutch.
The New England colonies had the advantage of being cohesive and egalitarian. They also had a strict culture that promoted educational development, and it's not a coincidence that some of the first centers of advanced learning in the United States were founded in New England (Harvard College, for example).
The Middle Colonies had the advantage of being more dynamic: because they enjoyed greater freedoms, they also attracted a larger pool of immigrants who provided a wide array of skills to develop the economy. With time, the Middle Colonies became the most populated in the United States, and the cities of New York and Philadelphia, acquired great importance.
