PSY 220 - Chapter 2.3

Epigenetics

"above the gene."

Range of Reaction

a wide range of potential expressions of a genetic trait, depending on environmental opportunities and constraints.

active gene-environment correlation

occurs when the child actively creates experiences and environments that correspond to and influence his genetic predisposition. For example, the child with a genetic trait for interest and ability in music actively seeks experiences and environments that support that trait, such as friends with similar interests and after-school music classes.

gene-environment interactions

refer to the dynamic interplay between our genes and our environment.

Heritability

refers to the extent to which variation among people on a given characteristic is due to genetic differences.

gene-environment correlation

refers to the idea that many of our traits are supported by both our genes and environment.

niche-picking

tendency to actively seek out experiences and environments compatible and supportive of our genetic tendencies.

Behavioral Genetics

the field of study that examines how genes and experience combine to influence the diversity of human traits, abilities, and behaviors.

passive gene-environment correlation

Parents create homes that reflect their own genotypes. Because parents are genetically similar to their children, the homes that they create are not only in line with their own interests and preferences, but they also correspond with the child's genotype. For example, parents might provide genes that predispose a child to develop music ability and also provide a home environment that supports the development of music ability, such as by playing music in the home and owning musical instruments. This type of gene-environment correlation is seen early in life because children are reared in environments that are created by their parents, who share their genotype.

epigenetic framework

The dynamic interplay between heredity and environment. From this perspective, development results from ongoing reciprocal interactions between genetics and environment.

Genotype

a biological influence on all of our traits, from hair and eye color to personality, health, and behavior.

evocative gene-environment correlation

a child's genetic traits (e.g., personality characteristics including openness to experience) influence the social and physical environment, which shape development in ways that support the genetic trait. For example, active, happy infants tend to receive more adult attention than do passive or moody infants, and even among infant twins reared in the same family, the more outgoing and happier twin receives more positive attention than does the more subdued twin. Why? Babies who are cheerful and smile often influence their social world by evoking smiles from others, which in turn support the genetic tendency to be cheerful. In this way, genotypes influence the physical and social environment to respond in ways that support the genotype. Children who engage in disruptive play tend to later experience problems with peers. To return to the music example, a child with a genetic trait for music talent will evoke pleasurable responses (e.g., parental approval) when she plays music; this environmental support, in turn, encourages further development of the child's musical trait.

Canalization

heredity narrows the range of development to only one or a few outcomes.

Phenotype

the traits we ultimately show, such as our specific eye or hair color, is not determined by genotypes alone. Phenotypes are influenced by the interaction of genotypes and our experiences.