Nurture, WEIRDness, and Complications: Do We Influence Our Children?

In 1998, Judith Rich Harris published The nurture assumption, a book that argued that parents had

little impact on their children’s development. This position was most annoying to many parents who

 had worked and worried to provide their children with parenting that (they hoped) would assure them

 with later happiness and success. Like most apparently simple positions, of course, Harris’s claim

 worked well only within certain boundaries. She did not argue that abusive parents and kind parents

 created the same outcomes, just that within a normal range of parenting behavior, what the parents did

was not the major factor determining child outcomes. Other important factors were the child’s and the

 parents’ genetic characteristics, school experiences, peer influences, extended-family influences,

religion, and community and national events.  In other words, Harris argued, on the basis of considerable research, not that parents were not important, but that other factors were quite important at all times and became more important as children got older.

It’s a common mistake to assume that whatever is true at one stage of life will necessarily continue to be true at other stages. Some rules of development seem consistent, but others change a good deal with age.

In addition, the term “developmental bias” is sometimes used to describe the assumption that whatever is happening now is based on events that happened early in life.  Later events can be caused by earlier events, of course, but it’s also possible that some experiences that make a lot of difference to a baby’s behavior may have nothing at all to do with later behavior and development. It might be that later experiences are so powerful that they just wipe out the early effects, or that maturational change causes reorganizations of behavior that leave behind any early events or experiences.  An example is the fact that babies who walk early and who walk relatively late (but within the normal range) really can’t be told apart later--  their walking and other movements are similar, and their early development and experience don’t seem to make any difference. Or, for another example, there are the descriptions from years ago of Russian babies who were swaddled a lot of the time until they were a year old and didn’t get much chance to crawl or pull to stand, yet it was reported that they walked at about the same time as babies who were encouraged to move around. 

The idea that it may be a mistake to assume that early experiences determine development is an important one as we argue about whether parents do or don’t influence children’s development. As Harris noted, there is a lot of evidence that events other than parenting are powerful shapers of children’s behavior and abilities. But at the same time we see increasing research reports that show how parenting may influence very young children.

Here’s an example of this kind of research, by Emily Little, Leslie Carver, and Cristine Legare (“Cultural variations in triadic infant-caregiver object exploration”, Child Development, 87, 1130-1145). Little and her colleagues were interested in the ways parents play with babies by using toys and objects—holding a toy for the baby to see, or helping the baby grasp it. Most of the research on this has been on people in the “WEIRD” population (Western, Educated, Industrialized, Rich, and Democratic), and “WEIRD” adults are known to choose to be face-to-face with babies while playing and to use object play as a teaching tool. Western psychologists have focused on this kind of interaction to the point where we look at babies’ use of social referencing (gazing toward an adult for a cue about a strange object) and joint attention as  essential developmental steps. But Little and her colleagues were curious about whether the rest of the world—the non-WEIRD part—behaved in the same way, and how children might be influenced differently.

Little and her colleagues decided to compare caregivers in the United States with caregivers on the island of Tanna in the Melanesian archipelago, a quite non-WEIRD place where subsistence farming and traditional life go on without compulsory schooling. (Other researchers like Barbara Rogoff have shown how children in this kind of society learn by watching adults more than by instruction.) The researchers looked at three ways the caregivers could interact with the children: using their voices, getting face-to-face and using the gaze to signal, or by physical contact (touching or holding the child, moving the child’s whole body and head, moving the body while holding the head still, moving the child’s body parts). As they played with the babies and the toys for three minutes, the U.S. group used their voices at about the same rate as the Tanna caregivers did. But the two groups reversed their use of visual and physical contacts--  the U.S. group used visual interaction more than twice as often as the Tanna group, and the Tanna group used physical interaction more than twice as often as the U.S. group. And what were the effects on the babies? There were not as many differences in infant behavior as Little and her colleagues had predicted, but the U.S. babies did look at the toy more often than the Tanna babies did—perhaps because of their previous experiences with caregivers who used their gaze to give and receive information. 

When Tanna babies and children later behave in ways that seem to reflect their caregivers’ early behavior, does that happen because of their experiences in infancy? Or are those experiences not nearly as important as their many later experiences, which will reflect the culture they live in? Either of these conclusions is possible in light of our limited information… limited because we see only a few people who move from a non-WEIRD infancy to a WEIRD childhood, and almost none who do the reverse. In either case, we need to remember that early experiences could be overwhelmingly important, or completely unimportant, or any point between—and what’s more, how that works could be different for each aspect of development. Like everything else about development, it’s complicated!