I am a broadly trained anthropologist with research and teaching interests that incorporate cultural, ecological, and evolutionary perspectives. My research interests are in human growth and development, reproductive decision making, fertility and health disparities. I have conducted field research in Bolivia exploring how socioeconomic change influences reproductive preferences and outcomes, the effects of adolescent reproduction on maternal and child growth and development, and the effects of mortality exposure on reproductive timing and effort.
With my post-doctoral advisor Mary Shenk (PSU), I manage a multi-site study investigating the psychological mechanisms underlying human reproductive decision making and the environmental cues these mechanisms are attuned to. There is a longstanding interest among demographers, anthropologists, and others, to explain how various socioecological factors influence reproductive preferences, timing and effort, and to separate correlates from causal factors. Consequently, we are also exploring the viability of using experimental methodology, especially priming, to separate causative relationships from correlative ones. In 2018, we begin our cross-cultural study to explore how cultural and economic differences affect the psychological mechanisms underlying our reproductive decision making.
Since 2005, facilitated by the Tsimane Health and Life History Project, I have worked with a population of South American forager-farmers, the Tsimane of Bolivia. This research has two foci: (1) how changing environments affect women’s and men’s fertility preferences and fertility, and consequently women’s reproductive health and autonomy; and (2) how adolescent mothers’ resource allocation — among the competing demands of growth, reproduction and somatic maintenance — affect their and their children’s health, growth and development.
Adolescent Pregnancy and Maternal and Infant Growth and Development
My first project with the Tsimane investigates the effects of early age at first birth and high fertility on maternal growth, health and cognitive development. Women have finite resources. Adolescence is a period of continued growth, and social and cognitive development. Reproducing during adolescence reduces women’s investment in their own growth and somatic maintenance but not completely, such that during gestation and lactation their first-born child receives fewer resources than the first-born children of women who delay their reproduction.
This work explores growth patterns in Tsimane women through adolescence, testing for trade-offs in energetic investment between growth and pregnancy. My findings, to date, support previous research suggesting that early age at first birth stunts maternal growth. However, my findings further suggest that: (1) women who give birth at age 15 or younger continue their growth post-pregnancy (although they are shorter as adults than average); (2) women on faster growth trajectories, do not cease growth earlier and are often taller than average as adults, if their growth is uninterrupted by pregnancy/motherhood; (3) the first-born sons, but not daughters, of mothers aged 15 and younger suffer long-term growth deficits. My future work in this area will investigate the long-term consequences of adolescent reproduction to the growth and health of first born and later born children; and the relationship between age at first birth and maternal and child cognitive development.
Women’s and Men’s Fertility Preference in a Changing Environment
My second project with the Tsimane explores why fertility among the Tsimane remains high (TFR = 9.1) despite small preferred family sizes (IFS = 4 to 5 children), and access to contraceptives and family planning programs. This high fertility, coupled with increasing infant and child survival rates, indicates that the Tsimane population will double in size within 24 years. As the Tsimane are marginalized, face discrimination and have limited land rights, this population growth and the associated environmental degradation are unsustainable. Furthermore, high fertility is associated with negative maternal and child health outcomes and low female autonomy. It is crucial that we better understand the dissonance between these people’s small desired family sizes and fertility, particularly as existing family planning programs and improved access to contraceptives are not having the expected affects.
My research suggests that excess fertility increases with proximity to market towns that provide resource stability and healthcare. Tsimane women living near these urban centers have better maternal condition and likely greater fecundity, which is not countered by increased use of contraceptives. Furthermore, they have low returns on investments in human capital and low socioeconomic mobility: Tsimane women are stuck in their homelands where adult status and success are measured in terms of reproductive status and family size, and sociopolitical power and economic security hinge on large kin networks. Under these conditions, despite a desire for smaller family sizes, women are trapped in a reproductive role, and motivation to delay or reduce reproduction is low. Consequently, adolescent reproduction is the norm for Tsimane women despite trade-offs between maternal and fetal/infant growth, development, cognition and health. However, the evolutionary, sociopolitical and long-term economic advantages (e.g. higher fertility) of an early reproductive start may outweigh these costs. My future work in this area will continue to unravel the interplay between socioeconomic development and evolved life history strategies at the onset of demographic transition.
I have taught several courses at the University of California, Santa Barbara, and been a guest lecturer at California State University – Channel Islands, and Santa Barbara City College. As I am trained in the biological and cultural sub-disciplines of anthropology, as well as demography, biology, and quantitative methods, I utilize a cross-disciplinary approach when teaching. I instruct my students how to use comparative and integrative methods in their research projects. I also believe students need marketable skills and incorporate training and practice of these into my courses.
McAllister, L., Pepper, G., Hackman, J., Virgo, S., Sobraske, K., Coall, D. (2016), The evolved psychological mechanisms of fertility motivation: Hunting for causation in a sea of correlation. Philosophical Transactions B. 371 (1692), Article no. 20150151
Coall, D. , Tickner, M., McAllister, L., Sheppard, P. (2016) Developmental influences on human fertility decisions: An evolutionary perspective. Philosophical Transactions B. 371 (1692), Article no. 20150146
Veile, A., Martin, M., McAllister, L., Gurven, G. (2014) Modernization is Associated with Intensive Breastfeeding Patterns in the Bolivian Amazon. Social Science & Medicine. 100: 148-158
McAllister, L., Gurven, M., Kaplan, H., Steiglitz, J. (2012) Why do women have more children than they want? Understanding differences in women’s ideal and actual family size in a natural fertility population. American Journal of Human Biology. 24(6):786-799
Gurven, M., Winking, J., Kaplan, H., von Rueden, C., McAllister, L. (2009) A bioeconomic approach to marriage and the sexual division of labor. Human Nature. 20(2):151-183
Sears, R., Pepper, G., McAllister, L. (2016) Demography needs you! Why demography needs psychologists. The Psychologist. 26(1): 26-29
In addition to my teaching experience, I have engaged undergraduates in my research. This has involved training undergraduates in analytical thinking, qualitative and quantitative research methods, statistics, project write up for publication, and presentation at conferences. Several students were also provided opportunities to do fieldwork in Bolivia and Bangladesh.
Undergraduate Projects Mentored
2017|Supervising Caitlin Paulson’s undergraduate honors thesis.
Title: Reassessing the relationship between propensity for risk taking and number of tattoos, and how tattoos are perceived in the 21 st century.
Supervised Ema Angeles’ original research project for the Undergraduate Research and Creative Activities Grant at UCSB.
Title: Why do the Tsimane evoke witchcraft to explain familial deaths?
2016|Supervised Madeleine Zoeller’s original research project.
Title: Does mortality risk influence parents’ investment in their children in Matlab, Bangladesh?
2015|Supervised Dylan Tweed’s original research project.
Title: Are Life History Variables Sensitive to Priming? A multi-level meta-analysis of 92 results from 41 studies.
Supervised Ivanna Robeldo’s original research project for the Undergraduate Research Colloquium at UCSB.
Title: Factors associated with Tuberculosis risk among Bolivian forager-farmers.
2012|Supervised Geni Garcia’s undergraduate honors thesis.
Title: The effects of Teenage Pregnancy on Maternal and Child Growth among Bolivian forager-farmers.