I agree it was in their blood to be ruthless, but what race isn't ruthless or has it in their blood in the Dragon Ball Universe, you know. Also, I just like the Sayians and Namekians because they are the only two races in the DBU that have the courage and aren't afraid to die for what they believe in.Goku was changed because he hit his head. Vegeta changed by choice. It was in their blood to be ruthless though and Frieza merely took advantage of that.