Genetic influences on development

Question 1

Gene-environment interaction

Answer 1

• refers to the influence of the relationship nbetween genotype and the environment in shaping a phenotype
  e. g phenylketonuria- genetic condition but can be modified by giving the child a specific diet and preventing intellectual disability

Question 2

Waddington

Answer 2

• concept of canalization
• some behaviour traits are genetically determined (canalized), so development follows these behaviours (e.g crawling)
• other behaviours are poorly canalized (e.g cycling) and so environmental factors will influence these traits
• some traits are heavily canalized in early development e.g language, but less so later on (reading ability)

Question 3

Gottesman

Answer 3

• notion of range of reactions
• genetic makeup of a child does not shape any behaviour in its entirety
• instead genetics only sets limits within which the individual variability is shaped by the environment

Question 4

Scarr and McCartney

Answer 4

• proposed the concept of ‘niche picking’ in developmental genetics
• genetic makeup of a child does not contribute to skills or behaviours as such
• genes only contribute to propensities toward certain skills and abilities; children then seek activities that are compatible with their genetic endowment

Question 5

Passive genetic-environmental interaction

Answer 5

• a child’s environment is influenced in part by parental genes which in turn are correlated with the child’s genes
• the phenotype is not a direct result of the child’s genotype but results from environmental influences that are indirectly associated with the parental genes
• this passive G_E will show decreasing influence over developments
  e. g a boy might not inherit his height genes from his dad but can still be good at basketball as his father takes him to lessons

Question 6

Evocative genetic-environmental interaction

Answer 6

• a child’s environment is influenced in part by genetically shaped behaviour
• the phenotype is not a direct result of the child’s genotype but results from environmental influences evoked by the child’s own genes
• this is a stable influence over development
• eg a girl who inherits impulsivity may evoke an abusive parental reaction, leading to later depression, though depression itself is not inherited

Question 7

Active genetic-environmental interaction

Answer 7

• a child’s environment is influenced in part by active choice of the child to complement genetically shaped interests
• phenotype is not a direct result of the child’s own genotype but results from environmental influences that are actively associated with the child’s own genes
• this shows increasing influence over development
  e. g a girl who inherits impulsivity may choose to gamble, losses in which may lead to depression although depression is not inherited