I wonder if this shitty Marxist study even attempted to address the fact that babies feel overall more secure around people who share similar physical characteristics with their parents, with skin color only being one of the determining factors, among many attributes. A stranger with features other than what the baby is used to, will lead to the child feeling anxiety, this much is common sense. We are speaking about a human being introduced to unknown concepts for the very first time in his life.
Are we supposed to "re-educate" the babies out of the natural instinct to cling onto their parents for safety, and to feel comfortable around them, so that they will become more accepting of strangers? This is some Soviet-level "experimenting" here. Legit KGB-style pseudo-scientific justification for taking babies out of the hands of their parents and "engineering" them to become more docile and helpless in a fucked-up society.