User blog comment:Hidden Scorpius XI/D-Piddy attacked by a Zwei cosplayer at Anime Expo 2015./@comment-25555436-20150711172511/@comment-82.46.35.19-20150712214835

Even if they do react, it may just be because infants, helpless things that they are, do not react well to the unfamiliar i.e a spider or something "terrifying". Instinctive response to danger. If a rabid dog was barking at them, I doubt they would respond well to that either. So the only thing that is genetic is the self-preservation instinct, which reacts to danger, whatever that may entail.