Female Humans 112 Male 112 child female 112 human 112 male preschool child Child, Preschool 108 Child 97 psychology 97 child parent relation 55 adult 49 adolescent 41 Adolescent 39 Adult 39 Article 37 controlled study 32 infant 32 Parents 31 physiology 31 major clinical study 30 Parenting 29 mother 28 Infant 26 article 25 longitudinal study 24 Mothers 23 Longitudinal Studies 21 child behavior 21