bio approach: genes & its effects on behaviour Flashcards
genetic mapping -
genetic mapping has revolutionized our understanding of how genes influence behavior. by identifying and locating specific genes within the human genome, scientists have uncovered genetic variations associated with various traits and behaviors.
epigenetics -
however, genes alone do not determine behavior. Epigenetics, the study of changes in gene expression without alterations to the DNA sequence, reveals how environmental factors can shape gene activity and behavior.
one area of interest in epigenetics + study linked to that
one area of interest in this field is the serotonin transporter gene (5-HTT), which is critical for regulating serotonin levels in the brain.
research by Caspi and colleagues (2003) has highlighted the complex interplay between genetic predisposition and environmental factors in behaviors like depression.
caspi et al. (2003) aim -
to investigate the role of the 5-HTT gene in developing depression in response to stressful life events.
caspi et al. (2003) sample -
longitudinal study - 1,037 children from New Zealand. participants were assessed from 3 to 26 years of age.
caspi et al. (2003) procedure -
all P were members of a cohort that had been assessed for mental health on an every-other-year basis until they were 21.
genetic mapping was used to divide participants into three groups based on their 5-HTT alleles.
grp 1 consisted of participants with 2 short alleles, group 2 had participants with 1 short and 1 long allele, and group 3 had participants with 2 long alleles.
the mutation of the 5-HTT gene has shorter alleles. roughly 43% of people have shorter alleles.
P were asked to fill in a “Stressful life events” questionnaire which asked them about the frequency of 14 different events - including financial, employment, health, and relationship stressors - between the ages of 21 and 26. they were also assessed for depression.
caspi et al. (2003) results -
P who had one or two short alleles of 5-HTT (group 1 & 2) reacted to stressful life events with more depressive symptoms. for example, participants who had a major stressful life event at age 21 tended to develop depression by age 26, but only if they carried a short allele of 5-HTT. the effect was strongest for those with three or more stressful life events.
simply inheriting the gene was not enough to lead to depression, but the genes’ interaction with stressful life events increased one’s likelihood of developing depression.
conclusion -
it was concluded that the 5-HTT gene is responsible for modulating an individual’s vulnerability to stress. This further supports the fact that genes influence human behaviour.
