Family planning is the usual modern route to producing a small family. Can human behavioral ecology provide a framework for understanding family planning behavior? Hillard S. Kaplan (Yearb. Phys. Anthropol. 39:91–135) has proposed a general theory of human parental investment based on the importance of skills development in children. As modern, skills-based, competitive market economies are established, parental investment strategies would be predicted to become oriented toward producing increasingly competitive offspring in a pattern of coordinated investment in their embodied capital—in (...) other words, skills training along with good health to ensure their long-term productivity. Parental embodied capital and resources are also expected to be associated with motivation to produce competitive offspring. The basic parental investment trade-off between quality and quantity should predict greater investment in fewer children and the adoption of family planning behavior. Data on family planning in two ethnic groups in Northeast India (Khasi and Bengali) currently experiencing early-phase transition into modern market economies from very different social and ecological baselines are examined within this analytical framework. The results show a mixture of strategies in conjunction with family planning that involve decreased as well as increased investment in the embodied capital of children among Bengali and a divergence of investments in education and health among Khasi. These mixtures of strategies provide some insight into the motivations to use family planning in the face of economic transition, given differing local cultural and ecological conditions and the opportunity structures they provide. (shrink)

Life history theory suggests that in risky and uncertain environments the optimal reproductive strategy is to reproduce early in order to maximize the probability of leaving any descendants at all. The fact that early menarche facilitates early reproduction provides an adaptationist rationale for our first two hypotheses: that women who experience more risky and uncertain environments early in life would have (1) earlier menarche and (2) earlier first births than women who experience less stress at an early age. Attachment theory (...) and research provide the rationale for our second two hypotheses: that the subjective early experience of risky and uncertain environments (insecurity) is (3) part of an evolved mechanism for entraining alternative reproductive strategies contingent on environmental risk and uncertainty and (4) reflected in expected lifespan. Evidence from our pilot study of 100 women attending antenatal clinics at a large metropolitan hospital is consistent with all four hypotheses: Women reporting more troubled family relations early in life had earlier menarche, earlier first birth, were more likely to identify with insecure adult attachment styles, and expected shorter lifespans. Multivariate analyses show that early stress directly affected age at menarche and first birth, affected adult attachment in interaction with expected lifespan, but had no effect on expected lifespan, where its original effect was taken over by interactions between age at menarche and adult attachment as well as age at first birth and adult attachment. We discuss our results in terms of the need to combine evolutionary and developmental perspectives and the relation between early stress in general and father absence in particular. (shrink)

Provides a comprehensive report on the mother-child bond and the emotional effects of and behavioral response to maternal deprivation.

This paper investigates hypotheses drawn from two sources: (1) Belsky, Steinberg, and Draper’s (1991) attachment theory model of the development of reproductive strategies, and (2) recent life history models and comparative data suggesting that environmental risk and uncertainty may be potent determinants of the optimal tradeoff between current and future reproduction. A retrospective, self-report study of 136 American university women aged 19–25 showed that current recollections of early stress (environmental risk and uncertainty) were related to individual differences in adult time (...) preference and adult sexual behavior, and that individual differences in time preference were related to adult attachment organization and sexual behavior. These results are consistent with the hypothesis that perceptions of early stress index environmental risk and uncertainty and mediate the attachment process and the development of reproductive strategies. On this view individual differences in time preference are considered to be part of the attachment theoretical construct of an internal working model, which itself is conceived as an evolved algorithm for the contingent development of alternative reproductive strategies. (shrink)

The current paper synthesizes theory and data from the field of life history (LH) evolution to advance a new developmental theory of variation in human LH strategies. The theory posits that clusters of correlated LH traits (e.g., timing of puberty, age at sexual debut and first birth, parental investment strategies) lie on a slow-to-fast continuum; that harshness (externally caused levels of morbidity-mortality) and unpredictability (spatial-temporal variation in harshness) are the most fundamental environmental influences on the evolution and development of LH (...) strategies; and that these influences depend on population densities and related levels of intraspecific competition and resource scarcity, on age schedules of mortality, on the sensitivity of morbidity-mortality to the organism’s resource-allocation decisions, and on the extent to which environmental fluctuations affect individuals versus populations over short versus long timescales. These interrelated factors operate at evolutionary and developmental levels and should be distinguished because they exert distinctive effects on LH traits and are hierarchically operative in terms of primacy of influence. Although converging lines of evidence support core assumptions of the theory, many questions remain unanswered. This review demonstrates the value of applying a multilevel evolutionary-developmental approach to the analysis of a central feature of human phenotypic variation: LH strategy. (shrink)

A modern evolutionary perspective emphasizing life history theory and behavioral ecology is brought to bear on the three core patterns of attachment that are identified in studies of infants and young children in the Strange Situation and adults using the Adult Attachment Interview. Mating and parenting correlates of secure/autonomous, avoidant/dismissing, and resistant/preoccupied attachment patterns are reviewed, and the argument is advanced that security evolved to promote mutually beneficial interpersonal relations and high investment parenting; that avoidant/dismissing attachment evolved to promote opportunistic (...) interpersonal relations and low-investment parenting; and that resistant/preoccupied attachment evolved to foster “helper-at-the-nest” behavior and indirect reproduction. (shrink)

Models of risk-taking as used in the social sciences may be improved by including concepts from life history theory, particularly environmental unpredictability and life expectancy. Community college students completed self-report questionnaires measuring these constructs along with several well-known correlates. The frequency of risk-taking was higher for those with higher future unpredictability beliefs and shorter lifespan estimates (as measured by the Future Lifespan Assessment developed for this study), and unpredictability beliefs remained significant after accounting for standard predictors, such as sex and (...) temperament. The results demonstrate the usefulness of applying concepts from life history theory to enhance our understanding of human behavior. (shrink)

The assumption that the onset of puberty is a context-sensitive marker of a reproductive strategy is tested by comparing parental and filial childhood context and somatic development in West and East Germany. Sixty-eight mother-daughter dyads and 35 father-son dyads were taken from two samples of families from Osnabrück in West Germany and Halle in East Germany. According to the observed context discontinuity between the generations in the male dyads, linear regression models show that no indicator of male sexual maturation was (...) influenced significantly by the somatic development of the father. Instead of an inherited timing of maturation, antecedent distal factors like socioeconomic childhood context variables and critical life events lead to an acceleration of male sexual maturation. Finally we test the effect of two different conditions of childhood context continuity on daughter’s age at menarche with maternal age at menarche controlled. Linear regression models show that mother’s age at menarche predicts daughter’s age at menarche only under the condition of contextual continuity between generations, which was the case in the West German sample only. In East Germany, where mother’s age at menarche had no significant effect, the amount of variance explained by childhood context variables was almost the same. These results indicate the context sensitivity of somatic development which seems to follow an evolutionary rationale. (shrink)

Parental investment strategies are contingent on parental capacities and ecology. Parental embodied capital may be important in aspiration construction and investments in children’s human capital, which is especially important in urban environments where skills are directly tied to wage income. For Indo-Fijians, rural ecology strongly limits opportunities. Here this limitation is conceptualized as extrinsic risk and immune to reduction through enhanced parental investment. Urban migration is interpreted as a risk reduction strategy, given an expanded urban opportunity structure (lower extrinsic risk). (...) Qualitative and quantitative data from 678 Indo-Fijian children suggest that, contingent on parental capacities, parents migrate in response to their perceptions of decreased opportunities that manifest as high levels of extrinsic risk in rural environments. Parental investment in quality and quantity corresponds to parental perceptions of extrinsic risk, which in turn correspond to migration status, indicating that parental strategies do respond to perceived limits on investment payoffs. (shrink)

Fascinating and controversial examination of how evolutionary theory sheds light on human nature using reproductive issues as a focus.