For a cross-sequential design, researchers _____

A student described an incident in which a man attacked a pedestrian and a bystander came to his rescue. The student suggested that the incident provided evidence of "an aggressive instinct and an altruistic instinct."

The class argued back and forth and finally turned to the instructor for guidance. What would a psychologist have to say about the topic of the class discussion? a) "A more likely explanation for the behaviors involves the needs hierarchy." b) "Only two instincts have been identified in human beings and they are not aggression and altruism." c) "Although instincts occur in some lower animals, in humans we cannot rule out learning explanations for such behaviors." d) "In order to understand these behaviors, we need to know about the participants' optimum levels of arousal, not instincts."

Which of the following is true with regard to the order of development of motor skills?

a. Babies develop motor skills based on what they see, so it is largely a function of imitation. b. Babies develop motor skills in very unique sequences, so there is no "order" of skills that is considered typical. c. Motor development in babies has two predictable paths – one for sighted children and one for blind children. d. Motor development tends to occur in a universal sequence and thus specific skills predictably develop before other skills.