I have 2 tables that have a many to many relationship; An Individual can belong to many Groups. A Group can have many Individuals. 

Individuals basically just have their Primary Key ID

Groups have a Primary Key ID, IndividualID (same as the ID in the Individual Table), and a bit flag for if that group is the primary group for the individual

In theory, all but one of the entries for any given individual in the group table should have that bit flag set to false, because every individual must have exactly 1 primary group.

I know that for my current dataset, this assumption doesn't hold true, and I have some individuals that have the primary flag for ALL their groups set to false.

I'm having trouble generating a query that will return those individuals to me.

The closest I've gotten is:

SELECT \* FROM Individual i 
LEFT JOIN Group g ON g.IndividualID = i.ID
 WHERE g.IsPrimaryGroup = 0

but going further than that with SUM or MAX doesn't work, because the field is a bit field, and not a numeric. 

Any suggestions?