Neuroticism is 40% - 60% heritable (Bouchard & loehin) so it is important to consider genetic contributions. It is found that there is a stronger genetic contribution in younger individuals with neuroticism traits as compared to older adults (more environmental influence) (Laceulle, Ormel). Other research has linked heighted brain reactivity in structures such as the amygdala along with reduced control by prefrontal structures (Keightelty et al. 2003). The amygdala is generally associated with fear and anxiety, which would mediate many traits of neuroticism. These exaggerated amygdala responses are linked to serotonin transporter gene (5HTTPR). Lastly, like with other disorders (e.g. schizophrenia) it has been found that the presence of a certain functional polymorphism allele can be associated with a disorder. In the case of neuroticism the presence of the s/s allele is associated (Montag , Basten 2010). Overall, these general biological factors can contribute to the development of …show more content…
These factors incorporate the environmental aspects that produce a sense of uncontrollability and unpredictability contributing to the development of neuroticism. This idea is supported by research regarding “experimental neurosis” that is, experimentally inducing anxiety to animals (e.g. excessive punishment, presentation of insoluble tasks, food deprived). A study by Roma et al. (2006) examined the effects of experimental necrosis within samples of rhesus monkeys. The researchers examined the level of anxiety by measuring corticopin-releasing hormone (CRH) in different food availability oriented situations. The results showed that monkeys that had greater control over food had lower cortisol activity. Along with this they found that infant monkeys with mothers who were experiencing ‘unpredictable forging conditions’ experienced greater leaves of CRH than infant monkeys raised with a consistent security of food (Coplan et al. 1996). Research regarding general psychological vulnerabilities have also been done in human studies. Research focused on the idea of locus of control (Rotter, 1966) that is individuals who report a more external than internal loss of control score higher on neuroticism scale. Chen and Zhou (2007) ran a meta-analysis of 100+ independent studies with 8,251 individuals to examine cortisol levels and the idea of locus of control. The results of the study found that