revision preference src: The preschool period involves the use of negotiation and bargaining. For example, four-year-olds are not distressed by separation if they and their caregiver have already negotiated a shared plan for the separation and reunion. <SEP> tgt: The preschool period involves the use of negotiation and bargaining. Four-year-olds are not distressed by separation if they and their caregiver have already negotiated a shared plan for the separation and reunion.