Point is, the whole gift giving/dropping/witholding might be a red herring, and perhaps the same results could be replicated by having both people give a toy to

Point is, the whole gift giving/dropping/witholding might be a red herring, and perhaps the same results could be replicated by having both people give a toy to a baby, but one acting scary and mean. And perhaps if two mannequins went through the same giving/dropping/witholding experiment, the result would not be observed. And perhaps if a smiling actress stole the toy, while a scowling actress dropped the toy, the affect would be reversed.