There are vast differences in early child-rearing environments across cultures. For example, the popular French documentary Babies, which documents the life of infants in five different cultures, depicts the multitude of ways infants can be raised across different ecological and cultural contexts.

These differences illustrate the reality of infants growing up in distinct contexts. Anthropologists have been documenting such variability for decades producing detailed ethnographies of parenting, family life and socialization practices across different cultural settings. Developmental psychologists have found that these early experiences shape human development.

Yet despite these fascinating differences, a whopping 95 per cent of developmental science is based on only five cent of the world's population.

The majority of developmental psychology studies are based on WEIRD societies: western, educated, industrialized, rich and democratic populations. Given this imbalance, one might wonder whether our knowledge of child development extends beyond urban, North American societies. The answer is, it depends.

In my research, I spend time with mothers, fathers, grandparents and babies to look at the ways in which they communicate, interact, teach and learn from one another. I am an associate professor of psychology at Simon Fraser University in British Columbia. I was trained by both a developmental scientist (Philippe Rochat at Emory University) and a bio-cultural anthropologist (Joseph Henrich at Harvard University).

I use my training in developmental methods to explore questions surrounding early experience and development across cultures. I have been fortunate to be welcomed into the homes of families in different corners of the globe.

Attachment parenting

For the past six years, I have been working primarily in one community in Vanuatu. Vanuatu is a group of islands, a three-hour flight from Brisbane, Australia.

Vanuatu was colonized by both the French and English. I have been working in a community on Tanna, Vanuatu. Historically, nearly half of the population on Tanna island has rejected colonization and all that it imposed: western education, languages and forms of religion. Therefore, Tanna has provided an interesting and remarkable forum for looking at socialization goals and developmental outcomes. Tanna is considered somewhat of a natural experiment for examining the impact of variation in socialization on development.

The official trailer of the French documentary, 'Babies' directed by Thomas Balmes.

For example, Heidi Keller, professor of psychology at Universität Osnabrück in Germany has recently suggested that one of the foundational human development theories, attachment theory, is western-biased and in need of revision. Attachment theory suggests that the bond (the first relationship) between a child and her caregiver is the foundational human relationship upon which all other relationships are built. Keller suggests, however, that our understanding of human development is based on child development as it occurs within the western context.

In our work, we examine caregivers and their infants in different societies, to determine the essential elements of child development.

What is common across cultures and what is different? Which theories need reformulation and which ones hold steady despite cultural differences?

Eye-tracking technology

In a recent study, my colleague Mikołaj Hernik and I used eye-tracking technology to compare the ways babies and caregivers communicate on Tanna. In this study, we showed babies short video clips with audio recordings of adults speaking in different ways: regular adult-directed speech and baby talk (or, infant-directed speech), and we observed and analyzed the way the babies responded.

We found that infants shifted their attention following the infant-directed speech, but not the adult-directed speech.

This suggests that infants on Tanna are using communication cues in strikingly similar ways to infants in other regions of the world.

This research, alongside other work examining infant development, suggests that parents and babies communicate in remarkably similar ways despite striking variation in cultural practices.

Tanya Broesch, Associate Professor, Simon Fraser University. This article is republished from The Conversation under a Creative Commons license. Read the original article.