Developmental Psychology Perspective on Development

Developmental Psychology

Perspective on Development

Development, like change, is the one thing constant that permeates throughout the lifespan of an individual. From birth until the later stages of life, human beings are constantly evolving and being transformed by both physiological processes and external experiences that define who they are and what they believe in. Although some theories on development are polarizing, it is widely accepted by experts that development is a product of nature-nurture (gene-environment) interaction. It is impossible to address one without the other; genetic expression cannot operate in a vacuum and conversely, without the individual, the environment will have nothing to act upon (Ansatsi, 1958, in Lerner, Theokas, & Bobek, 2005). Hence, when describing a particular view on development, it is logical and ecologically valid to do so in light of this interaction.

The current perspective addresses two main issues in developmental psychology: personality and cognitive development. The discussion on personality development is focused on early childhood influences such as maternal care quality, as this is widely believed to be a significant factor in shaping the emerging personality of a child. Two theories on cognitive development are then explained and appraised in terms of how they adapt or exclude the nature-nurture premise of development.

Development starts from birth and if there's one thing that arrives full-strength at this moment, it's temperament. Many experts agree that temperament has an in-built biological basis (Connell, 1976; Aters, Vaughn, & Egeland, in press; Ainsworth, 1979; in Ainsworth, 2001). Temperament may affect a parent's response toward their children. This response then forms part of an environment that parents can help to change in order to make a difference in their child's developing personality.

There is some evidence that at least during the early years, a child's emerging personality has more to do with maternal behavior and child care practices than built-in potential and temperament (Ainsworth, 2001; Baumrind, 2001). The quality of mother-child interactions such as feeding, physical contact, and other face-to-face encounters are believed to influence an infant's reaction to new situations (Ainsworth, 2000; Hane and Fox, 2006). For instance, infants who receive high quality maternal care at home are shown to be less distressed and more exploratory in a new environment than those who do not (Ainsworth, 2000). On the other hand, infants whose mothers are not responsive to their needs and have a particular aversion to holding them are more anxious and avoidant compared to infants whose mothers display the opposite behavior at home (Ainsworth, 2000).

Other studies have shown that the above pattern is consistent even during the later pre-school years. Self-controlled and buoyant children tend to have parents who are firm and demanding (with reasonable expectations) but communicative (Baumrind, 2001). In contrast, insecure and dependent children tend to have mothers who don't exert parental control and are moderately loving (Baumrind, 2001). These findings don't imply that a child's personality is fixed during the early years. They do suggest, however, that during this critical stage, mothers and primary caregivers have the best opportunity to positively shape a child's personality.

Personality evolves over time and emerges more complete later in life. in-between, many factors feed into it, including culture, environment, socio-economic factors, and unique experiences. Personality also plays an important factor in decision-making, such that when individuals learn different things from the same experience leading them to two different pathways, it is attributed to personality differences. This is illustrated in a recent study where a group of young students taught in the same stock market investing class eventually displayed either positive, negative, or mixed investing expectancies in practice investment sessions (Smith et al., 2006). It is proposed that this difference in expectancies can be attributed to personality-dependent behavioral stimulus of reward or punishment. Interestingly, these stimuli are also perceived to have a genetic origin (Caspi & Roberts, 2001, in Smith et al., 2006). Although this study has some limitations, it provides empirical suggestion that personality attributes can lead to differential learning experiences and thus to different maturation pathways among adults (Smith et al., 2006).

Cognitive development is another major issue in developmental psychology. The acquisition of learning and formation of cognitive structures is viewed differently by many authors and experts. There are two main contentions so far: one, cognitive development occurs in a ladder-like fashion with discrete stages that increasingly progress in power and generality (Case, 2008) and two, learning is dynamic and occurs at multiple levels at any one stage, much like a developmental web (Fischer and Rose 2008).

The first view -- also known as the traditional "Piagetian" model of cognitive development -- assigns specific cognitive milestones in children to a specific age range, provided that children have been exposed to an optimal environment (Case, 2008). Children then assimilate experience to their existing cognitive structures, undermining the role of external influences in the formation and alteration of these structures (Case, 2008). This view can be considered flawed, first in light of the premise of gene-environment interaction, and second, in the seeming implication that a child's intellectual benefits can be diminished by cultural and linguistic heritage (Case, 2008).

The latter view, on the other hand, proposes that both brain and behavior undergo common growth cycles over an individual's lifespan to accompany physical changes in the brain (Fisher and Rose, 2008). In this model, cognitive growth is malleable when children live and learn in adequate environments, implying that individuals can relearn skills they didn't develop earlier if future situations are more nurturing (Fisher and Rose, 2008). Hence, this model has the characteristic of plasticity and is more consistent with the nature-nurture interaction premise of development.

This being said, cognitive development is tightly linked to brain development, which is to a great extent under tight genetic control. Developmental milestones such as the development of speech, word recognition, and the formation of abstract concepts are controlled by genetic timing under specific stages of early childhood development (Vygotsky, 1954; Shonkoff and Philips, 2000; Friend, DeFries, & Olson, 2008). However, as the opening paragraph of this paper illustrates, the expression of genes always takes place in the context of interaction with environmental stimuli. Knowing this underscores the importance of creating conditions that will enhance or moderate the genetic propensity towards certain cognitive attributes and behavior.

Personality and cognitive abilities are just two of the many planes that make-up the multifaceted nature of human development. While these two areas have been discussed like two distinct concepts in this paper, the processes involved in each all act in concert to create a unique developmental experience for each individual.

Q2. Nature-Nurture Interaction

The nature-nurture theory of development is a classic view that's highly esteemed by psychologists, scientists, and behavioral experts alike. It states that both gene and environment play an interactive role to produce systematic changes and stabilities in the lifelong development of an individual. In other words, a person is a product of his inherent characteristics and unique experiences. This being said, the traditionalist nature-nurture view emphasizes that characteristics are constrained by genes and induced by the environment. This differential approach is manifested not only in how developmental studies and research are often designed but also in public discourse and policy debates on child and family issues (Shonkoff & Philips, 2000). This traditionalist view is controversial because it invariably elicits a despondent opinion about certain negative behavior and psychological disorders; i.e., if you can't blame it on nurture, then blame it on nature and vice versa.

Over the last few decades, this either-or approach to the nature-nurture issue is slowly being reconceptualized to accommodate groundbreaking studies in human behavior through molecular and behavioral genetic research. At the core of modern behavioral research findings is that gene expression is inconceivable apart from its environment, either that within or outside the body. Hence, instead of nature vs. nurture, it is rather nature through nurture (Shonkoff & Philips, 2000). This paper attempts to explore some gene-environment (G XE) interactions by citing empirical evidence from recent molecular and behavioral genetics studies. Specifically, these studies show how nature moderates nurture and vice-versa. Further, the theory of GXE correlation, or how GXE interactions can have a reciprocal nature, is also explored.

Gene-environment interaction is nowhere more critical in a person's life than during his childhood. It is widely believed that a child's temperament, although innate, can be significantly shaped by external influences such as family upbringing and other unique experiences. However, there are certain behaviors that seem to be tightly controlled by genetic predisposition, regardless of the nurturing environment. One of these is aggression. In both mice and human, aggression and antisocial behavior are both linked to low levels of an enzyme called MAOA (Caspi et al., 2002). It is hypothesized that childhood maltreatment is more likely to result in adult violence among children whose MAOA levels are not enough to neutralize brain chemicals associated with antisocial and violent behavior (Caspi et al., 2002). This is used to explain results of previous studies that most maltreated children do not, in fact, turn out to be delinquents despite a 50% increased chance of criminality in adulthood (Wisdom, 1997, in Caspi et al., 2002). It is now widely believed that vulnerability to bad behavior is conditional and depends on genetic susceptibility (Kendler, 2001; Rutter & Silberg 2001; in Caspi et al., 2002).

This theory was tested by Caspi et al. (2001) when they attempted to predict antisocial behavior among more than 1000 male maltreated children by genotyping their polymorphism at the MAOA gene. Their findings provided epidemiological evidence that high MAOA expression moderates the effect of maltreatment and partially explained why not all victims of maltreatment grow up to retaliate by victimizing others (Caspi et al., 2001). In this case, genotype (polymorphism at the MAOA gene) is shown to moderate children's sensitivity to environmental insults (maltreatment).

Having said that there are certain characteristics where genes play a moderation role to the environment, the opposite can also be true. One of these characteristics is cognitive ability among children. It is widely accepted that cognitive and academic outcomes like IQ can be predicted by environmental factors such as socio-economic status or SES (Friend, DeFries, & Olson, 2008). One measure of SES is parental education, which gives an indication of the level of investment in a child's education and performance in school (Craig, 2006, in Friend, DeFries, & Olson, 2008). Parents who are highly educated tend to have the resources to create an environment that enhances learning among their children. For children who develop learning disabilities despite a nurturing environment, the bioecological model of GXE of interaction is proposed; that is, genetic influences on behavior should be most evident when the environment is supportive (Ceci, 1994, in Friend, DeFries, & Olson, 2008).

In a study of more than 500 identical and fraternal twins, it was found that on average, the heritability of reading disability (the most common form of learning disability) was more a function of genes rather than environment among children whose parents had a higher level of education, compared to those whose parents had a lower level of education (Friend, DeFries, & Olson, 2008). In other words, children who failed in reading despite having a nurturing environment tended to have stronger genetic influences on their reading disability than did children who had less nurturing environments as far as reading is concerned.