4% of people was/were

Question

What is grammatically correct:

saying “4% of people was classified as introverts”.

Or saying

4% of people were identified as introverts.

The context is that I’m reporting the results of a survey.

Answer 1

If the noun that follows a percentage of is plural, use a plural verb after it:

e.g. 45% of people are(NOT is) interested in politics.

e.g. Just 50% of U.S. adults now get (NOT gets) news regularly from television, down from 57% a year prior in early 2016.

And about your own example:

4% of people were (NOT was) identified as introverts.