Heck, this is nothing new. Animal breeders have known about this stuff since forever.
For example, this is what dogbreedinfo.com has to say about the "Labradoodle": FAULTS: Yappy, highly strung, dominance/aggression, fearful/timid, aggressive toward other animals. Dogs showing any of these behaviors should not be bred.
IOW, you assume that the personality traits are inherited, and you take animals with bad traits out of the gene pool.