Which disorder commonly occurs with borderline personality disorder?

Which of the following questions would be MOST relevant to information-processing researchers?

A) Are there any similarities in language development across cultures? B) Do children solve problems more quickly working collaboratively or alone? C) Why does memory strategy usage increase with age? D) Do parenting styles influence aggressive behavior in preschoolers?

By about ________ of age, a child can solve invisible displacement problems

A) 3 months B) 6 months C) 18 months D) 2 years