Board Thread:Manga/@comment-26495049-20161117013314/@comment-24404665-20180426023318

Most of this thread pre-dates Chapter 96, which confirms that the minorities of Paradis (nobles, and by extension Ackermans) are in fact Eldians, but of a different race.

Kenny's grandfather has already confirmed that their bloodline is not of the majority race within the Walls, that being the Subjects of Ymir. Rod's comment about Uri being unable to control Kenny due to the latter's Ackerman heritage also supports this. No reason why they would lie.

How "Titan science" works is largely unknown.