The question of how dependent a child’s temperament is on their environment, biology and other individual differences has been the subject of much debate in the world of psychology. To critically discuss to what extent such factors have on temperament, we should consider what this term means- “individual differences in emotional, motor, and attentional reactivity and self-regulation” (Rothbart, 1998, p.105-76). This definition considers the child’s emotional responses; physical ability; how passionate or responsive the child is and how regulated their sleeping and eating habits are, for example. Possible influences on temperament are ‘nature’, including innate characteristics, and ‘nurture’, the child’s early life environment and socialisation.
A child’s early life environment itself is affected by a number of factors, such as social-economic status; parenting; culture; school entry age and extracurricular activities to name a few. For the purpose of this essay, the focus will be on social-economic status and parenting.
Firstly, individual differences were noted for dimensions such as distractibility and intensity of reaction in children in Chess &Thomas’ (1987, as cited in Roberta, 2009) development of the 9 NYLS (New York Longitudinal Study) dimensions on child temperament. Some newborns were found to cry a lot louder than others if hungry, which showed more apparent “intensity” in the child’s temperament. This indicates that temperament is a result of innate characteristics as at such a young age, little environmental influence is likely to have taken place. Behavioural profiles were also produced using the dimensions and 3 types of temperament were developed from this: “Easy”, “Difficult” and “Slow to warm up”, which were apparently identifiable in children as young as 2-3 years old. There is evidence that caregivers’ awareness of such individual differences is highly important as this can affect the child’s socialisation process developing in early life. For example, those with a “Difficult” temperament might have more intense reactions and harsher parenting techniques used as a result may not always be helpful. Therefore, though aspects of a child’s temperament can be seen as innate, environmental factors and social influences also hold a degree of influence. Parenting practices should be adapted to a “Difficult” child in order for the parent to optimise their ability to nurture their child’s temperament. The NYLS dimensions are still in use today and the construct of child ‘difficultness’ has been further developed and used in many other measures. However, this could cause issues when considering such research as results will depend on which measure and definition of ‘difficultness’ is being referred to.
Secondly, Kagan’s (1994) work (as cited in Chess & Alexander, 1996) studied temperament by also using a biological approach. 43 children had their heart rates recorded and were observed and rated during 2 simple laboratory tasks. Statistical analysis was used to assess the difference between behavioural inhibitions of the children. Inhibition serves certain social functions such as preventing impulse acts, for example, losing your temper and hitting someone. This relates to impulsivity as an aspect of one’s temperament. It was found that inhibited children had a higher and more stable heart rate than uninhibited children. At approximately 5.5 years old, there were a number of significant correlations between heart rate and physiological factors such as pupil dilation during cognitive stress and adrenaline levels. This suggests that individual physiological differences are indicative of varying temperaments in children, in line with other biological studies (Fox & Calkins, 1993 as cited in Rubin et al., 1993). Nevertheless, Kagan commented that environmental factors should be investigated too in order to gain a full picture.
The effects of social-economic status can be seen in Dearing et al.’s (2001) work investigating associations between children aged 1-36 months and effects of changes in family income by 36 months. Results showed a significant effect of income on children from poor families but no significant effects of income on non-poor families. For families in poverty, children’s school readiness; expressive language and positive social behaviours were negatively affected and behavioural problems more prominent and vice versa. Such research gives support for environment affecting a child’s temperament, even at the early age of 36 months. Also, a higher risk for negative outcomes at 36 months was found for those that had spent longer in poverty. Even so, associations cannot be directly translated as causal relationships. It is difficult to be certain that extraneous variables, such as parenting; genetic ability and school standards did not affect the results recorded. Differences could have been due to variables other than family income but the effect of the duration spent in poverty discourages this assumption.
Parenting practices and child temperament were investigated using the questionnaire method. Parent perceptions of toddlers’ social wariness and shyness at 2 years old predicted their preferences for socialisation strategies at 4 years old (Rubin, Nelson Hastings & Asendorpf, 1993). Observations of child-parent interactions were also recorded. It seemed that those parents perceiving their children to be shy, somewhat limited their child’s opportunities for independence. This was more evident in those parents that were more anxious. Such parenting styles could make it more difficult for self-regulation to develop and for potential interactions with other children to take place. Those children less capable of self-regulation at an early age may develop independent feeding skills later than others for example, which would probably negatively affect temperament with more irritability occurring during meal times. So not only are parenting styles an influence on temperament, parents’ perceptions of their child’s abilities and temperament (inclusive of the factors defined by Rothbart, 1998) and how this affects their child-rearing is also extremely relevant. As parent perceptions were being studied, the questionnaire method used is quite fitting. Despite this, we should take into account social desirability bias and demand characteristics potentially affecting validity. For example, parents may be unwilling to convey their children as shy due to partaking in psychological research.
Studies on twins have been carried out in attempt to determine whether biological or environmental factors attribute to a child’s temperament. Spinath & Angleitner (1998) collected separate mother and father ratings on 354 monozygotic and dizygotic twins ranging from ages 2-14. The twins’ Emotionality, Activity, Sociability and Shyness were also assessed using the EAS Temperament Survey (Buss & Plomin, 1984, as cited in Spinath & Angleitner, 1998). On all EAS dimensions, except “Emotionality”, dizygotic twins showed negative or near-zero correlations and the similarities between monozygotic twins were more than half those held by dizygotic twins. As dizygotic twins are expected to experience similar environmental stimulation, it seems that the much stronger correlations between monozygotic twins’ similarities would arguably be explained by their genetic similarity. Related findings seem to be obtained in further behavioural genetics research (Kimberly & Saudino, 2005) which supports the importance of innate characteristics in temperament. Nevertheless, we cannot be sure whether parents’ ratings were affected by demand characteristics and therefore, the validity of the similarity ratings made between the twin pairs. It could even be argued that similarities were rated on “perceived zygosity” – that is to say, perhaps parents and rating family members perceived more similarities between monozygotic twins because of their physical similarities. Experimental methods would conceivably be more useful for identifying the genetic factors contributory to temperament, but familial observations over time may well be more valid, naturalistic observations of child temperament and similarities. Although such research may suggest that the greater monozygotic correlations support the importance of biology in child temperament, results do not explain how relevant it is and certainly does not definitively give evidence for the nature or nurture debate. For more clarity, it seems that a combination of methods should be used to explore the dimensions of temperament. Perhaps teacher ratings could have been used in addition to parent and family member ratings alone. Exploring more “within-family” differences (Kimberly & Saudino, 2005) to account for differential treatment of children within the same family, for example, offers more insight to why different family member’s temperament can vary across a whole range of behaviour.
A greater understanding of the influences on child temperament has major practical implications. For example, certain teaching techniques may help “Difficult” children focus more in school and increase their productivity as a result. Biological influences are arguably less important, as it would imply that temperament is less changeable than a lot of research seems to suggest. For example, a child of “slow to warm up” temperament, whilst explicable by nature, could benefit greatly from practice of specifically identified socialisation skills. In addition, labelling children with certain temperaments could prove detrimental to their developing temperament during early years and being aware of this is exceptionally important.
To conclude, there is evidence to advocate both nature and nurture contributions to child temperament. Although there is significant evidence for biology’s role in temperament, there seems to be a general consensus that environmental factors are ultimately of higher importance, as human experiences and surroundings are so varied from person to person. To better understand child temperament, we should look at the interaction of such biological and environmental factors more closely rather than isolating them. A good example is portrayed by Chess & Alexander (1987, as cited in Roberta, 2009), where individual differences from birth are apparent, but, what marks a difference is how those innate characteristics are dealt with by parents, and the effect this will have on other social interactions and thus, how child temperament is developed early on in life.