Sandra Teen Model Early Sets Img 12
Sacha Weakland
CONTEXT: Compared with children of older women, children of women who had their first birth during their teens have long been believed to be at higher risk for a host of poor health, social and economic outcomes. Recent studies have failed to confirm this belief, but none have taken into account whether children's outcomes or the effects of early childbearing on those outcomes have changed over time.
METHODS: Data from the National Longitudinal Survey of the Labor Market Experience of Youth and the Panel Study of Income Dynamics are used to separate the influence of changes from the 1960s through the 1990s in children's experiences from the effect of mother's age at first birth.
CONCLUSIONS: Comparisons by age at first birth among women born in the same period may misestimate the effects of early motherhood. Whether early childbearing's effects on children are overestimated or underestimated depends on whether test scores are rising or falling. Policymakers should be cautious in making decisions based on studies that do not take time trends into account.
RESULTS: Multivariate analyses controlling for social and demographic characteristics show that among children born to women from a particular birth cohort, those whose mothers first gave birth in their teens have significantly lower scores on a set of four achievement tests and significantly higher scores on a behavior-problem index than do children whose mothers delayed childbearing. However, when changes over time in children's outcomes and in the effect of early childbearing on those outcomes are taken into account, children born to women who began childbearing early score significantly worse than those whose mothers delayed their first birth on the behavior-problem index, but on only one achievement test.
Most studies find that children of teenage parents are at greater risk than children of older parents for a host of health, social and economic disadvantages.1 As a result, they score lower on standard intelligence tests and achievement evaluations.2 Their risk is elevated partly because their mothers are disadvantaged to begin with and partly because their mothers tend to attain less schooling, to remain single or to have unstable marriages, and to have more children than average. Other research, however, suggests that there is no difference or even that children of younger mothers have certain advantages.3 The relationship between a teenage birth and disadvantage becomes small or disappears altogether once controls are introduced for background differences and intervening factors.4 The exact mechanisms that affect children may differ at different times and for different outcomes; for example, biological factors may operate on health at birth, while environmental factors may affect cognitive and social development.5 This conundrum has yet to be well described, let alone explained.
Most analyses examining the effects of teenage childbearing on children have used the National Longitudinal Survey of the Labor Market Experience of Youth (NLSY), a cohort of youth first interviewed in 1979, when they were aged 14-21. Because this research was conducted using data collected in the 1980s, most comparisons are between teenage mothers and women who had a first birth in their early 20s. However, first children born to women aged 20-21 may also suffer some of the detrimental effects associated with teenage childbearing.6 Thus, these comparisons may have underestimated the effects of early childbearing. It is important to replicate these earlier analyses to see whether the results are the same when the full range of ages at first birth is used.
In addition, it is important to determine whether the results are affected by the limitations of available data. The appropriate comparison is between all children of all women (regardless of age at first birth) who bore a first child in a given time period. Yet, the NLSY data set requires pooling children born to teenage women in the 1970s with children born in the mid-1990s to first-time mothers in their 30s. The circumstances surrounding giving birth in the 1970s may be very different from those today. In analyses of the effect of maternal age, the age of the mother is confounded with the period of observation. Effects found in analyses that do not control for differences in birth periods may result from a changing environment rather than from varying maternal age.
Some researchers argue that as the women in a cohort study such as the NLSY enter their 40s, data on newborn children can be added, to allow comparisons between all children born to teenage mothers and all those born to later childbearers.7 The validity of this approach is dependent on the assumption that neither the outcomes for children nor the effects of teenage childbearing change over time. Because NLSY respondents whose first birth occurred in 1980 were considerably younger than those who first gave birth in 1995, analyses using the survey data cannot separate the effect of maternal age from that of historic period.
This article examines the implications of period change for the consequences for children of having been born during their mother's teenage years. Do children's achievements change over time? Do the effects of timing of childbearing on children's achievements vary by whether the first birth occurred in the 1970s, 1980s or 1990s? We attempt to answer these questions by constructing a data set comparable to the NLSY from the Panel Study of Income Dynamics (PSID), which includes data on early and later childbearers in the same historic periods.
It has long been believed that an early birth disadvantages a young mother's children as well as the woman herself. One key reason is that early childbearing interferes with the process of schooling and human capital development, which means that the mother's ability to garner resources will be reduced. She is much more likely to be poor than is a woman who delays childbearing, for example.8 This may prevent her from providing resources that promote cognitive development, such as a high-quality child-care arrangement and a stimulating home environment.
Second, because young mothers are socially and emotionally immature, we would expect them to have limited parenting ability. Coping with the demands of an infant is likely to be far more challenging for a teenager than for an older woman.9 Inconsistent and arbitrary discipline, which is more common among young mothers, has a negative impact on children's behavior and on their social and emotional development.10 As a result, we expect a young age at first birth to adversely affect children's social and emotional adjustment. Even if a teenage mother has additional children when she is older, she may continue the patterns of parenting she established with her first child. Teenage mothers also tend to provide their children with less cognitive stimulation and less emotional support than do older mothers: One study found that scores on a global measure of parenting were lower for the homes of children of teenage parents than for the homes of other children.11
First, women who have a child at a young age differ initially from those who do not. Their mothers' education is lower, they are more likely to come from a single-parent family and they have more siblings.13 Such young women are less likely to delay sexual activity, and are more likely to bear and raise a child if they become pregnant.14 Given these disadvantages, even if they delayed childbearing, their children might not be better off.
In addition, early childbearing may have advantages for physical well-being, because both adolescents and their children tend to be quite healthy. From this perspective, being born to an adolescent mother may not be a disadvantage, particularly if she received adequate prenatal and postnatal care.15
Researchers have used a variety of methodological techniques to control for factors that influence both achievement and early childbearing. Controlling for observed factors reduces the relationship between teenage motherhood and measures of vocabulary recognition (the Peabody Picture Vocabulary Test), math and reading comprehension (the Peabody Individual Aptitude Test), and behavior problems.16 In one study, the introduction of such controls eliminated the relationship in the case of the math and reading comprehension tests.17
Some factors associated with early childbearing, however, cannot be measured. Controlling for unobserved factors common to siblings reverses the direction of the effect of a teenage birth, so that children of young mothers do better than children born to older mothers on the vocabulary, math and reading comprehension tests.18
Researchers have puzzled over these results for some time; the only explanation proposed is that previous studies misestimated the effects of early childbearing because they left out important observed variables, such as maternal ability or birth order,19 or unmeasured family factors.20We propose, instead, that period effects are the key omitted variables.
First, we hypothesize the existence of a pure period effect. If children's test scores and behavior are changing over time, and we compare teenage mothers in an earlier period with adult childbearers in a later period, we cannot be sure whether we are estimating the effect of early childbearing or the effect of period changes in scores. If test scores are declining, the children of teenage mothers may appear similar to those of later childbearers because the former were assessed in a period when scores were higher; any disadvantage resulting from young maternal age may be offset by the period effect. If scores are rising, the children of later childbearers will have the advantage, not only because they were born to older mothers, but also because the scores of all children are higher. Increases in test scores over time should lead to improvements in scores for all children, but should not necessarily result in advantaging or disadvantaging the children of teenage mothers as long as comparisons are made within the same period.
7fc3f7cf58