Exercise 1

Chapter 4 illustrates a number of the issues discussed in "The Nature of Development'' presented in Chapter 1. Which of the following topics taken from Chapter 4 correctly illustrates the Chapter 1 topic paired with it in terms of prenatal or postnatal development of the fetus or infant? Circle the letter of the best answer and explain why it is the best answer and why each other answer is not as good.

1. . germinal, embryonic, and fetal periods: stability
2. embryonic development: maturation
3. teratology: biological determinants and influences
4. miscarriage/abortion: discontinuity
5. The Power of Touch and Massage in Development: early experience

Exercise 2

The endpiece called "The Power of Touch and Massage in Development" describes two intervention studies done with low-birthweight and preterm infants. These studies are important because they evaluate ways to improve the care of infants. An important aspect of evaluating these studies, however, is identifying the research techniques used in them. Which of the following pairs of terms best represents this intervention research? Circle the letter of the best answer and explain why it is the best answer and why each other answer is not as good.

1. correlational, cross-sectional
2. correlational, longitudinal
3. experimental, cross-sectional
4. experimental, longitudinal
5. both correlational and experimental, and cross-sectional and longitudinal

Exercise 3

Methods for supervising and assisting childbirth have changed considerably in the past two decades. Your text describes the basics of today's methods as well as a number of new and experimental practices. An interesting feature of current practices is that they represent a renewed assumption about the process of childbirth that did not get much emphasis in the more physician-controlled practices of previous years. Which of the following is a statement of assumption, rather than an inference or an observation? Circle the letter of the best answer and explain why it is the best answer and why each other answer is not as good.

1. Most current methods are based on Grantley Dick-Read's concepts.
2. The father may not be the best coach during labor.
3. Active breathing is associated with less pain during delivery.
4. Women know how to give birth.
5. Including siblings in the birth presents sibling rivalry.

ANSWER KEYS FOR CRITICAL THINKING EXERCISES

Exercise 1

1. No, these do not illustrate the concept. Prenatal development is a period of rapid and radical change, not stability. These phases better illustrate periods of development.

2. This illustrates the concept. Embryonic development is perhaps the best illustration of a clear, orderly sequence of changes that most likely are dictated by a genetic blueprint. An indication is that this period of prenatal development is least susceptible to damage from teratogens; if there is too much environmental interference, the organism aborts.

3. This does not illustrate the concept. Teratogens do influence biological development, but they are environmental influences.

4. No, these do not illustrate the concept. The concept of discontinuity is that development produces qualitatively new and different features, often in what appears to be a progression of stages. These events represent an end to development.

5. No, this does not illustrate the concept. The focus of the endpiece about Tiffany Field's work on massage is not whether massage has a key influence on the long-term development, but how massage can benefit the immediate growth of infants who receive it. The more relevant developmental issue is the influence of experience (nurture) on what might seem like an entirely biological process.

   Exercise 2

   1. No, these studies are not correlational nor are they cross-sectional. Infants were assigned to experimental or control conditions, and the same groups were studied over time. That makes the work experimental and longitudinal.

   2. See A.
   3. See A.
   4. See A.
   5. See A.

   Exercise 3

   1. This is an observation. It is based on comparison of various techniques and their acknowledged debt to the work of Dick-Read.

   2. This is an inference. It represents a reasoned judgment based on the idea that men do not experience childbirth.

   3. This is an observation. Physicians have noted this about women who practice active breathing when they deliver their babies.

   4. This is the assumption. It is stated plainly in the text without justification, argument, or evidence. It is also not clear precisely what the statement means!

   5. This is an inference. It is based on the notion that children grow worried and jealous when their parents exclude them to devote time and attention to their newborn sister or brother.