In another classic study, McGraw (1940) measured the effects of very earh training on twins. She put one twin on the toilet every hour of every day from Z months of age, but did not put the other twin on until 23 months. The first twin began to show some control at 20 months, and by about 23 months he had achieved almost perfect success. The other twin quickly caught up. It seem-SHOULD

BABIES USE INFANT WALKERS?
could walk, and perhaps even help her to walk earlier. But then they heard some disturbing stories about babies who had suffered accidents in these walkers, and they wondered whether it would be a mistake to put their child into it. Ellen and Charles's fears, unfortunately, were justified. Walkers have been very popular over the past few decades: in 1980, about 1 million were sold in the United States, and an estimated 55 to 86 percent of babies are put into them (Ridenour, 1982; Rieder, Schwartz, & Newman, 1986). Some of these babies hurt themselves badly. In 1980, 24,000 walker-related injuries were reported in the United States. Most of the injuries came from the baby's tipping over the walker or falling down steps while in it. In 1984 in a single Toronto hospital,  139 children were treated forsuch injuries as skull fractures (accounting for 75 percent <¦• injuries in this group) and fractures of such exposed bod. parts as forearm, clavicle, and nose. One 6-month-olc baby died after falling down 14 steps and hitting its head or a concrete floor (Rieder et al., 1986). Even after their ace dents, many of the babies in the Toronto study continued t< be placed in their walkers. One-third of the babies stopper using them only after they learned to walk.

Walkers do serve as a mechanical baby-sitter, keeping babies happy, and they do seem to help babies with som. of the cognitive gains associated with locomotion (Ber-tenthal, Campos, & Barrett, 1984). However, they do n< ¦ help babies learn to walk any earlier (Ridenour, 1982). Thi-finding is additional evidence that motor control develop-at its own natural pace and that efforts to speed it up art likely to be useless or even harmful (Gesell, 192(< McGraw, 1940).

After they learned the facts, Ellen and Charles decider: that the risks of infant walkers outweighed the benefits, anr: that this was one piece of modern equipment their moder baby would be better off without.

 INFANCY AND TODDLERHOOD
dear, then, that for some abilities—like the control of elimination—experienceu training counts for little if the child is not mature enough to benefit from it.
Over the past few years, however, some parents have put their babies inntant walkers, partly to amuse the babies but partly to encourage them to walk
 arlier. As Box 5-4 shows, these appliances do not help babies walk earlier, andhev do pose serious risks.

Death in Infancy
One of the most tragic losses is the death of a child. Even though the parents of a baby who has died have not had the chance to get to know their child well, :hev are usually deeply grieved. Parents may say that their arms "ache to hold their baby," and they are often overwhelmed by depression (National SIDS Clearinghouse, undated).

I NFANT MORTALITY
Ae have made great strides over the years in protecting the lives of newbornbabies. Today in the United States the infant mortality rate—the proportion of    infant mortality rate babies who die within the first year of life—is the lowest in the country's history.  Proportion of babies who die In 1985 there were fewer than 11 deaths for every 1000 live births, a 63.7 percent    within the first year °f life-improvement over the 29.2 per 1000 in 1950 (National Center for Health Statistics, 1987). However, while infant mortality rates among both whites and blacks have declined, the rate for blacks (at 18.2) continues to be about twice that for whites (Wegman, 1987).

The gap becomes more pronounced after the first month of life, possibly because socioeconomic factors become more influential— and because more black than white families are at low socioeconomic levels. Furthermore, it comes as a shock to realize that in terms of infant mortalitv, the United States ranks only nineteenth among 25 countries with a population of more than 2.5 million (Wegman, 1987). (See Figure 5-5, page 186.)
Besides the important health problem represented bv these babies' deaths which represent the largest number of deaths in anv single year of life up to age ^5), infant mortality is the tip of an iceberg—a sign of children's health problems in general (American Academv of Pediatrics Task Force on Infant Mortality, 1986). By analyzing the unhappy picture of infant mortality, we can better understand the health needs of children, and indeed of the entire population. We can, for example, learn about factors affecting pregnancy and birth as well as babies.

The term neonatal mortality refers to death in the first 4 weeks; postneonatal mortality refers to death in the rest of the first year. Neonatal mortality, which accounts for 70 percent of deaths in the first year, has two major causes. One is congenital defects (defects present at birth); this is the only cause of infant mortality that does not affect blacks more than whites (Wegman, 1987). The other major cause, which accounts for 70 percent of neonatal deaths, is low birth-weight (discussed in Chapter 4). This affects black babies more than twice as often as white babies: 12.4 percent of black babies, compared with 5.6 percent of white babies, weigh less than 5Vi pounds at birth (Wegman, 1987). The considerable decline in neonatal mortality since the late 1960s is due to medical advances in keeping very small babies alive and in treating sick newborns.