We have parents registering kids for classes and events. Many times, these are new children to our database.  For certain events, we need the child's age and/or gender.  And, we may want to add them as a constituent. At this time, we have to use Event Participant Attributes to capture this data just for that one specific event. If the child already has a record, but we are missing birth date information, this data does not actually get into the child's record.