passive correlation: parents and children share the same genotype and the same environment. For example, parents pass on genes related to a difficult trait and express this difficult trait through irritable and negative parenting behavior, which in turn is related to the child’s difficult trait. In a child-based construct, this correlation would be categorized as “shared environment influence”, whereas in a parent-based construct, it would be categorized as “genetic factor influence”;
– evocative or reactive correlation: this results from a reaction of the environment to a characteristic of the child under the influence of genetic factors. Parents react to the child’s difficult character with harsh and negative parenting, a “coercion cycle”; a happy child provokes different reactions from a gloomy child, for example. There is a growing acceptance of the idea that children influence how they are treated by others, including their parents, and that parents react differently depending on the child. Adoption studies are the most relevant in highlighting evocative correlations, as they provide information about the biological parents. For example, if we know the psychopathology or addiction of the biological parents, then we can see how it increases the risk of such problems in the adopted child, problems that will in turn influence the parenting behavior of the adoptive parents;
– active correlation: the child actively selects environments that are correlated with his or her genetic characteristics (this is more often true for peers than for parents) or that his or her perceptions of events are genetically influenced (a suspicious child will generally perceive his or her parents’ behavior more negatively than a confident child and will act accordingly; a depressed adolescent will isolate himself or herself and inhibit influences from his or her parents).
We must understand all these processes that build parental behavior and its adaptation to the child if we want to be able to improve dysfunctions and their consequences.
1.5. Childhood and culture, anthropological approaches
The vast majority of research in the field of developmental psychology suffers from a strong sampling bias: 91% of the studies focus on children in wealthy, industrialized, democratic Western societies; moreover, even in these societies, children from the middle and upper classes are overrepresented1.
Work in anthropology and cross-cultural psychology allows us to overcome these knowledge limitations through two approaches: a depth or precision approach, which often relies on detailed and deeply contextualized ethnographic data, typically from one society, and a breadth or size approach, which relies more on experimental data from standardized tasks deployed in many different societies. These two approaches are complementary, each with its own strengths and weaknesses (see Amir and McAuliffe (2020)).
1.5.1. The phylogenesis of childhood
Like other primates, young humans are dependent on others for long periods after weaning and exhibit a unique life history stage called infancy. Follow-up fossil evidence such as the eruption of the first, second and third molars suggests that the duration of this stage of life history has more than doubled over the past 4 million years.
This lengthening and dependence are at the heart of hominization2, the concept of “neoteny” describes this immaturity at birth of the human baby compared to other species, but it is precisely this immaturity that will allow the development of specifically human characteristics. For example, the infant chimpanzee dominates the infant human in the first months of life in all types of tasks and tests, then progressively, this ratio will reverse.
The length of childhood will allow the human child to acquire an enormous amount of information, directly through its own observations and actions, as well as indirectly through a complex cultural transmission. Moreover, human populations, having colonized the entire planet, live in very different geographical, climatic and social environments, hence the concept of “adaptive phenotypic plasticity” which describes the capacity of an organism to adapt its development to environmental conditions (Amir and McAuliffe 2020).
Adaptation for the individual will consist of developing phenotypes that are suitable to environmental conditions from the start of life; variations in behaviors will result from the responses to the different socioecological indices.
An empirical and developmental example of this type of prediction is that a child’s neighborhood hardship enables his or her prosocial behavior to be predicted in an experimental game: children living in difficult, low-income neighborhoods exhibit less prosocial behavior toward strangers than children in less difficult, higher-income neighborhoods. These patterns mirror those observed among adults living in similar economic conditions (Safra and Tecu 2016).
Development during childhood is a period of heightened sensitivity to environmental indices and developmental research in this area tends to exploit variations in these indices as natural experiments to determine downstream behavioral consequences.
A different, but largely compatible, perspective is that derived from “culture-gene coevolution” theory: like adaptive phenotypic plasticity, this approach also offers a rich perspective on child development, but focuses relatively more on the role of cultural transmission in early childhood (Amir and McAuliffe 2020).
This approach draws on the social learning model and focuses on the variation of cultural norms and their internalization as a driving force for behavioral variation across societies; cultural norms are behavioral heuristics that individuals tend to follow when: (1) a sufficiently large number of community members conform to them – the so-called “empirical expectation” (descriptive norms) – and (2) a sufficiently large number of community members expect the individual to conform, also called “normative expectation” (injunctive norms).
Initial propensities for social learning are likely to be equivalent in all populations, and these shared propensities then interact with varying cultural norms across societies to produce variations in behavior. Cross-cultural work distinguishes the characteristics of our psychology and behavior that are sensitive to cultural input in varying degrees.
In contrast to the concept of universality, which assumes that a phenomenon would be observed everywhere in the world, cross-cultural developmental psychology advances the concept of regularity (Rogoff 2003), to track and measure the regularities of child behaviors and developmental trajectories in various environments.
For example, the rejection of an allowance when they receive more than another person seems to appear with some regularity in children in different societies, which does not irrevocably demonstrate that the aversion to having more than another person is universal, but the regularity of its occurrence may lead to new research questions. For example, can the roots of this form of aversion be traced phylogenetically? Can formal models of cooperative interactions foster inequity aversion? Thus, cross-cultural developmental studies can contribute to broader theoretical and evolutionary debates about human behavior (Amir and McAuliffe 2020).
1.5.2. Theoretical models on the influence of culture on development
A great many theoretical models exist to explain the influence of culture on the child: Bronfenbrenner’s ecological systems model (1977), Whiting’s psychocultural research model (1977), Vygotsky’s sociocultural-historical theory (1980), Harkness and Super’s developmental niche model (1994), Weisner’s ecocultural model (2002), Rogoff’s transformation of participation approach (2003), Keller’s ecocultural model of child development (2013) and Worthman’s bioecocultural model of child development (2010).
A general characteristic of these models is that they all seek, in one way or another, to contextualize child development as a dialog between
