The question evokes the early-20C notion of Eugenics, and we all know who did most to ensure the pseudo-science was rightly rejected, though in a terrifyingly ironical way that involved millions of people dying.
The question also evokes some science-fiction writers of the time, who essentially asked a similar question to determine the logical but dystopian ends.
Those people did not know genetics at a molecular level as the subject was not yet understood, but they were all familiar with Genetic Modification in practice, to produce domesticated plants and animals. They just didn't have the GM term; though it was still GM albeit indirectly rather than in a chemistry laboratory.
Whilst one could make a fair case for preventing disabilities or propensity to dangerous physical illnesses, manipulating emotion and intellect would be horrific because it removes the subject's individuality - existence as a person - merely to suit others' vanity or desires to control that person.
Most people do not hate or lie gratuitously, or by some sort of genetic defect. Deceit and hatred are generally engendered by external pressures, not some aspect of molecular biology. They may be wrong, but they are not genetic illnesses.
Nanoose 