This 2014 primate study found:

“Oxytocin increased infants’ affiliative communicative gestures and decreased salivary cortisol, and higher oxytocin levels were associated with greater social interest.”

One would have to take an anti-evolutionist stance and believe that primates do not feel what humans feel to consider this process to NOT be cruel:

“To test these macaques, we took advantage of ongoing experiments requiring infants to be separated from their mother on the day of birth. Infants were nursery-reared, housed individually, with a cloth surrogate mother. They could see and hear other infants, but could not touch them.”

We know that primate infants, like humans, need “nourishment, transportation, warmth, protection, and socialization” from their mothers. What level of findings about oxytocin can a research study make that would justify this deprivation?

It surely wasn’t the findings this study made. We knew without doing the study that getting oxytocin from a nebulizer would be nowhere near an acceptable substitute for a mother’s touch and care.

http://www.pnas.org/content/111/19/6922.full “Inhaled oxytocin increases positive social behaviors in newborn macaques”