Among infiuential explanations of why preschoolers are so drawn to pretending, Freud's psychoanalytic theory and Piaget's cognitive theory held sway for much of the twentieth century.
( ( Among ( ( infiuential explanations ) ( of ( why ( preschoolers ( ( are so ) ( drawn ( to pretending ) ) ) ) ) ) ) ) ( , ( ( ( ( ( Freud 's ) ( psychoanalytic theory ) ) and ) ( ( Piaget 's ) ( cognitive theory ) ) ) ( ( ( held sway ) ( for ( much ( of ( the ( twentieth century ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN Among) (NP (NP (JJ infiuential) (NNS explanations)) (PP (IN of) (SBAR (WHADVP (WRB why)) (S (NP (NNS preschoolers)) (VP (VBP are) (ADVP (RB so)) (VP (VBN drawn) (PP (TO to) (NP (NN pretending)))))))))) (, ,) (NP (NP (NP (NNP Freud) (POS 's)) (JJ psychoanalytic) (NN theory)) (CC and) (NP (NP (NNP Piaget) (POS 's)) (JJ cognitive) (NN theory))) (VP (VBD held) (NP (NN sway)) (PP (IN for) (NP (NP (RB much)) (PP (IN of) (NP (DT the) (JJ twentieth) (NN century)))))) (. .)))
Prior to the twentieth century, there were no explanations for why preschoolers like pretending.
( ( Prior ( to ( the ( twentieth century ) ) ) ) ( , ( there ( ( were ( ( no explanations ) ( for ( why ( preschoolers ( like pretending ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (RB Prior) (PP (TO to) (NP (DT the) (JJ twentieth) (NN century)))) (, ,) (NP (EX there)) (VP (VBD were) (NP (NP (DT no) (NNS explanations)) (PP (IN for) (SBAR (WHADVP (WRB why)) (S (VP (VBZ preschoolers) (PP (IN like) (S (VP (VBG pretending)))))))))) (. .)))