Your a idiot. There stuttering has nothing to do with mental or physical strength/efficiency. You act like it's a mental retardation that effects IQ. It's a slight handicap, most caused by childhood trauma or high stress in early development stages. You'd rather have a lower IQ less stronger non stutterer around or a highly capable productive stutterer?...if you want to not have sex and possibly not have kids who probably won't even stutter because it's something that doesn't always get passed on genetically then that's on you...people who are in high stress environments develop stutters also. So it's not always a genetic thing.