PERSONALITY PSYCHOLOGY DOMAINS OF
KNOWLEDGE ABOUT HUMAN NATURE
COMPREHENSIVE TEST PAPER QUESTIONS
AND SOLUTIONS GRADED APLUS
●● genetic junk
Answer: The 98 percent of the DNA in human chromosomes that are not
protein-coding genes; scientists believed that these parts were
functionless residue. Recent studies have shown that these portions of
DNA may affect everything from a person's physical size to personality,
thus adding to the complexity of the human genome.
●● eugenics
Answer: The notion that the future of the human race can be influenced
by fostering the reproduction of persons with certain traits and
discouraging reproduction among persons without those traits or who
have undesirable traits.
●● percentage of variance
Answer: Individuals vary or are different from each other, and this
variability can be partitioned into percentages that are related to separate
causes or separate variables. An example is the percentages of variance
in some trait that are related to genetics, the shared environment, and the
unshared environment. Another example would be the percentage of
,variance in happiness scores that are related to various demographic
variables, such as income, gender, and age.
●● heritability
Answer: A statistic that refers to the proportion of observed variance in a
group of individuals that can be explained or "accounted for" by genetic
variance (Plomin, DeFries, & McClearn, 1990). It describes the degree
to which genetic differences between individuals cause differences in
some observed property, such as height, extraversion, or sensation
seeking. The formal definition of heritability is the proportion of
phenotypic variance that is attributable to genotypic variance.
●● phenotypic variance
Answer: Observed individual differences, such as in height, weight, or
personality.
●● genotypic variance
Answer: Genetic variance that is responsible for individual differences
in the phenotypic expression of specific traits.
●● environmentality
Answer: The percentage of observed variance in a group of individuals
that can be attributed to environmental (nongenetic) differences.
Generally speaking, the larger the heritability, the smaller the
environmentality. And vice versa, the smaller the heritability, the larger
the environmentality.
,●● nature-nurture debate
Answer: The ongoing debate as to whether genes or environment are
more important determinants of personality.
●● selective breeding
Answer: One method of doing behavior genetic research. Researchers
might identify a trait and then see if they can selectively breed animals
to possess that trait. This can occur only if the trait has a genetic basis.
For example, dogs that possess certain desired characteristics, such as a
sociable disposition, might be selectively bred to see if this disposition
can be increased in frequency among offspring. Traits that are based on
learning cannot be selectively bred for.
●● family studies
Answer: Family studies correlate the degree of genetic overlap among
family members with the degree of personality similarity. They
capitalize on the fact that there are known degrees of genetic overlap
between different members of a family in terms of degree of
relationship.
●● twin studies
Answer: Twin studies estimate heritability by gauging whether identical
twins, who share 100 percent of their genes, are more similar to each
other than fraternal twins, who share only 50 percent of their genes.
, Twin studies, and especially studies of twins reared apart, have received
tremendous media attention.
●● monozygotic twins
Answer: Identical twins that come from a single fertilized egg (or
zygote, hence monozygotic) that divides into two at some point during
gestation. Identical twins are always the same sex because they are
genetically identical.
●● dizygotic twins
Answer: (also called fraternal twins) Twins who are not genetically
identical. They come from two eggs that were separately fertilized ("di"
means two; so dizygotic means "coming from two fertilized eggs").
Such twins share only 50 percent of their genes with their co-twin, the
same amount as ordinary brothers and sisters. Fraternal twins can be of
the same sex or of the opposite sex.
●● equal environments assumption
Answer: The assumption that the environments experienced by identical
twins are no more similar to each other than are the environments
experienced by fraternal twins. If they are more similar, then the greater
similarity of the identical twins could plausibly be due to the fact that
they experience more similar environments rather than the fact that they
have more genes in common.
●● adoption studies
KNOWLEDGE ABOUT HUMAN NATURE
COMPREHENSIVE TEST PAPER QUESTIONS
AND SOLUTIONS GRADED APLUS
●● genetic junk
Answer: The 98 percent of the DNA in human chromosomes that are not
protein-coding genes; scientists believed that these parts were
functionless residue. Recent studies have shown that these portions of
DNA may affect everything from a person's physical size to personality,
thus adding to the complexity of the human genome.
●● eugenics
Answer: The notion that the future of the human race can be influenced
by fostering the reproduction of persons with certain traits and
discouraging reproduction among persons without those traits or who
have undesirable traits.
●● percentage of variance
Answer: Individuals vary or are different from each other, and this
variability can be partitioned into percentages that are related to separate
causes or separate variables. An example is the percentages of variance
in some trait that are related to genetics, the shared environment, and the
unshared environment. Another example would be the percentage of
,variance in happiness scores that are related to various demographic
variables, such as income, gender, and age.
●● heritability
Answer: A statistic that refers to the proportion of observed variance in a
group of individuals that can be explained or "accounted for" by genetic
variance (Plomin, DeFries, & McClearn, 1990). It describes the degree
to which genetic differences between individuals cause differences in
some observed property, such as height, extraversion, or sensation
seeking. The formal definition of heritability is the proportion of
phenotypic variance that is attributable to genotypic variance.
●● phenotypic variance
Answer: Observed individual differences, such as in height, weight, or
personality.
●● genotypic variance
Answer: Genetic variance that is responsible for individual differences
in the phenotypic expression of specific traits.
●● environmentality
Answer: The percentage of observed variance in a group of individuals
that can be attributed to environmental (nongenetic) differences.
Generally speaking, the larger the heritability, the smaller the
environmentality. And vice versa, the smaller the heritability, the larger
the environmentality.
,●● nature-nurture debate
Answer: The ongoing debate as to whether genes or environment are
more important determinants of personality.
●● selective breeding
Answer: One method of doing behavior genetic research. Researchers
might identify a trait and then see if they can selectively breed animals
to possess that trait. This can occur only if the trait has a genetic basis.
For example, dogs that possess certain desired characteristics, such as a
sociable disposition, might be selectively bred to see if this disposition
can be increased in frequency among offspring. Traits that are based on
learning cannot be selectively bred for.
●● family studies
Answer: Family studies correlate the degree of genetic overlap among
family members with the degree of personality similarity. They
capitalize on the fact that there are known degrees of genetic overlap
between different members of a family in terms of degree of
relationship.
●● twin studies
Answer: Twin studies estimate heritability by gauging whether identical
twins, who share 100 percent of their genes, are more similar to each
other than fraternal twins, who share only 50 percent of their genes.
, Twin studies, and especially studies of twins reared apart, have received
tremendous media attention.
●● monozygotic twins
Answer: Identical twins that come from a single fertilized egg (or
zygote, hence monozygotic) that divides into two at some point during
gestation. Identical twins are always the same sex because they are
genetically identical.
●● dizygotic twins
Answer: (also called fraternal twins) Twins who are not genetically
identical. They come from two eggs that were separately fertilized ("di"
means two; so dizygotic means "coming from two fertilized eggs").
Such twins share only 50 percent of their genes with their co-twin, the
same amount as ordinary brothers and sisters. Fraternal twins can be of
the same sex or of the opposite sex.
●● equal environments assumption
Answer: The assumption that the environments experienced by identical
twins are no more similar to each other than are the environments
experienced by fraternal twins. If they are more similar, then the greater
similarity of the identical twins could plausibly be due to the fact that
they experience more similar environments rather than the fact that they
have more genes in common.
●● adoption studies
