Chapter Concept Check Answers

Concept Check 1

• Teratogens are agents such as drugs, viruses, and diseases and conditions such as malnutrition that impair prenatal development and lead to birth defects or even death. Thus, they are not due to heredity (nature). They are prenatal environmental factors, and therefore their effects are due to nurture.
• Habituation, a decrease in physiological responding to a stimulus once it becomes familiar, is used to determine what stimuli an infant can perceptually discriminate. The inference is that if an infant looks longer at a new stimulus than an old one, then the infant must be able to perceive the difference. In addition to looking, researchers use other measures such as changes in the rates of sucking on a pacifier and the infant’s heart rate.

Concept Check 2

• Overextension and underextension in language development involve using a word too broadly or too narrowly, respectively. Through experience we learn to extend a word’s meaning correctly. Overextension can be viewed as overassimilation—incorrectly attempting to assimilate the new object into the existing schema for the word when accommodation is necessary. Underextension can be viewed as underassimilation—failing to assimilate the new object into the existing schema for the word. In overextension, the child assimilates when he needs to accommodate, and in underextension, the child does not assimilate when he needs to assimilate.
• A child who thought that a pizza cut into eight slices was more than the same pizza cut into six slices would be in the preoperational stage, because she is not demonstrating knowledge of conservation. She is centering her attention on the number of slices and not the size of the slices.
• Together these two concepts, zone of proximal development and scaffolding, comprise a teaching method. First, the zone of proximal development (the difference between what a child can actually do and what the child could do with help) is determined. Then scaffolding (adjusting the level of help in relation to the child’s level of performance) is used to structure and guide the learning to the upper level of the child’s zone of proximal development.
• In a cross-sectional study, groups of participants of different ages are studied at one point in time. In a longitudinal study, one group of participants is studied at many different points in time as the group ages. The cross-sectional method is less time-consuming and expensive but subject to cohort effects created by factors unique to each generation in the study. Because the same participants are tested at different ages, the longitudinal method is not subject to such effects; but due to participant attrition, sample-group changes over time may impact the results.

Concept Check 3

• The response indicates that Heinz should not steal the drug because he would be caught and sent to jail—punished. Even if he weren’t caught, his conscience would punish him. Thus, Kohlberg would classify this explanation for not stealing the drug as reflective of Stage 1 (punishment orientation) in which people comply with rules in order to avoid punishment.
• An infant’s temperament is the set of innate dispositions that lead him to behave in a certain way. It determines the infant’s responsiveness in interactions with caregivers, how happy he is, how much he cries, and so on. The temperaments of infants vary greatly. Those that fit the child-rearing expectations and personality of the caregivers likely facilitate attachment formation. Difficult infants probably do not.
• Authoritarian parents are demanding and expect unquestioned obedience, are not responsive to their children’s desires, and do not communicate well with their children. Authoritative parents, however, are demanding but reasonably so. Rather than demanding blind obedience, they explain the reasoning behind rules. Unlike authoritarian parents, they are both responsive to and communicate well with their children.
• A child without understanding of false beliefs would predict that Big Bird will look for the ball in the toy chest where Cookie Monster has rehidden it, because the child does not understand that others can have beliefs that disagree with his. If the child has an understanding of false beliefs, he would predict that Big Bird will look in the box where he had earlier put the ball because he realizes that others can have beliefs that disagree with his.
• Erikson thought that at each stage there is a major psychosocial issue or crisis (e.g., identity versus role confusion) that has to be resolved and whose resolution greatly impacts one’s development. For each crisis, there is a positive adaptive resolution and a negative maladaptive resolution. When an issue is positively resolved, social competence increases and one is more adequately prepared for the next issue.