Does a fare that says 4 people include the driver?

Nope! The driver is not included in the capacity

No, if the capacity states as "4 people", it means your group can incude 4 people. (5 including the driver)

Be aware that drivers are mandated by the rideshare companies to make sure they have the capacity advertised.  This means that the drivers cannot have their friends or pets in the car or have objects occupying any of the seats.

You may also be interested in this question from a driver:
Can my girlfriend/spouse/friend/etc. ride along with me on a uber shift?

ippei 1202

Uber Driver, CEO of TaxiFareFinder and Unleashed, LLC