1. The answer is b. The average newborn in the United States weighs 3.27 kg. Infants gain 680 g per month until about age 5 to 6 months, by which time their birth weight has doubled. Birth weight triples by the end of the first year, to approximately 10 kg.

2. The answer is d. Feeding, especially breastfeeding, is a learned behavior that contributes to self-regulation in infants and to sensitive responding in mothers. Mothers and infants learn to coordinate supply and demand of milk, especially during the first few weeks of life. This give-and-take requires that mothers learn to read infants’ signals of hunger, fatigue, distress, and satisfaction. As infants learn to regulate the flow of milk, they also learn to organize their own behavior. Feeding, especially at the breast, helps them to calm down and focus. An attentive infant in the arms of a responsive mother is ready to interact with her, to focus his or her eyes on her face, and to listen to her voice.

3. The answer is c. Head control is a good indicator of brain maturation. Newborns cannot lift their heads until they are 6 weeks old, and then do so briefly. By 3 to 4 months, they raise their head, shoulders, and upper abdomen while supporting themselves on their forearms. When newborns are pulled to sit, their head falls back. Head lag decreases and infants have steady head control by 5 to 6 months, when they can sit with support.

4. The answer is d. At birth, visual acuity is about 20/100 and steadily improves. Newborns can see and fixate on objects within 20 cm of the center of their bodies. Thus objects within close range, such as the mother’s face, are perfectly clear. A preference for patterns is evident within hours after birth. Patterns that are somewhat complex and that have moving parts, especially the human face, are of greatest interest.

5. The answer is a. Apgar scores are used as a rough assessment of immediate adjustment to extrauterine life. Heart rate, respirations, muscle tone, reflexes, and skin color are assessed at 1 and 5 minutes after birth, with each being given a score of 0, 1, or 2. Total scores less than 3 indicate severe distress. Scores of 4 to 6 signify moderate difficulty, and scores of 7 to 10 indicate no difficulty adapting to extrauterine life. Apgar scores are affected by prematurity and maternal medication, but are not indicative of the presence or absence of neurological or physical abnormalities.

6. The answer is a. Newborn behavior has four characteristics. Inborn physiological mechanisms, such as reflexes, enhance survival. Newborns organize their behavior in response to stimuli (e.g., turning their head in response to a sound). They respond selectively to certain stimuli (e.g., patterns of light and dark). Newborns demonstrate contingency-seeking behavior; that is, they look for predictability in the environment, for events that go together. In a classic experiment, DeCasper and Fifer demonstrated that infants learn to adjust their rate of sucking by using the mother’s voice as a reward. That is, infants learned that hearing their mother’s voice was contingent on how fast they sucked on a pacifier.

7. The answer is b. The complex cognitive activities that slowly appear throughout development are rooted in the association area and testify to the interaction between body and mind.

8. The answer is a. Once neural induction begins, the nervous system development process is swift and steady. Any interference with the process (disease, chemicals) can produce serious damage.