Originally Posted by MonoVCPHG
Jealousy is observed in infants 6 months old. It's not a social construct in it's basic form. Social conditioning can shape the manifestation and expected reactions to it, but it exists as a documented emotional response.
Competing for a mother's milk isn't exactly the same as being jealous. That sounds like a little projection there. Besides, even infants imitate what they observe around them at a very early age. Studies have shown that infants begin imitating facial movements of those around them as early as one hour after birth. They develop the same facial expressions of the people they see all the time; when a baby learns to walk, they adopt the gait and armswing of the parents they see most often; and when they begin to vocalize, they imitate the tone and cadence of their caregivers. Jealousy is quite possibly something else that is observed and imitated. By the time a kid is about seven years old, the cake is baked and they have already made choices unconsciously about strategies for living. I learned this when I was studying bodywork and have seen these things firsthand when I used to take care of my friends' babies.