Nature, nurture, and human diversity

Behavior Genetics

The study of the
relative power and
limits of genetic and
environmental
influences on
behavior.

Heredity

The genetic transfer
of characteristics
from parents to
offspring

(Eg. Height and eye
color influenced by
parents)

Environment

Every nongenetic influence, from prenatal nutrition to the people and things around us. (Eg. Parenting styles and education)

Chromosome

Structure made of DNA molecules that contains the genes.

DNA

AKA Deoxyribonucleic
acid.A complex molecule
containing the
genetic information
that makes up the
chromosome

Genes

The biochemical
units of heredity that
make up the
chromosomes; small
segments of DNA
capable of
synthesizing
proteins.

Genome

The complete
instructions for
making an organism,
consisting of all the
genetic material in
that organism’s
chromosomes.

Monozygotic
twins

Identical twins

Dizygotic twins

Fraternal twins

Temperament

A person’s
characteristic
emotional reactivity
and intensity.

(Eg. A shy baby is
cautious and slow to
warm up)

Heritability

The proportion of
variation among
individuals in a group
that we can attribute
to genes.

(Eg. Intelligence is
partly heritable but
schooling and culture
play a role)

Interaction

The interplay that
occurs when the effect
of one factor (such as
environment) depends
on another factor
(such as heredity).

(Eg. Genetic risk for
depression may only
show if triggered by
stressful life events)

Molecular
genetics

The subfield of
biology that studies
the molecular
structure and
function of genes.

Molecular behavior
genetics

The study of how the
structure and
function of genes
interact with our
environment to
influence behavior.

Epigenetics

The study of the
molecular mechanisms
by which environments
can influence genetic
expression (without a
DNA change).

(Eg. Stress can
activate genes
associated with
anxiety)

Culture

The enduring
behaviors, ideas,
attitudes, values, and
traditions shared by a
group of people and
transmitted from one
generation to the next.

(Eg. Greeting styles,
parenting styles,
dietary patterns, etc)

Norm

Understood rules for
accepted and
expected behavior.
Norms prescribe
“proper” behavior.

(Eg. Individuals from
certain countries use
only their right hand
to eat)

Individualism

Giving priority to one’s
own goals over group
goals and defining
one’s identity in terms
of personal attributes
rather than group
identifications.

Collectivism(Eg. Focussing on what
do “I” want)

Collectivism

Giving priority to the
goals of one’s group
(often one’s extended
family or work group)
and defining one’s
identity accordingly.

(Eg. Focussing on what
is best for the
group/family)

Biological sex

In psychology, the
biologically influenced
characteristics by
which people define
male, female, and
intersex.

Gender

In psychology, the
behavioral
characteristics that
people associate with
boy, girl, man, and
woman.

Intersex

Possessing male and
female biological
sexual characteristics
at birth.

Aggression

Any physical or verbal
behavior intended to
harm someone
physically or
emotionally.

(Eg. Physical violence
such as hitting and
pushing, verbal insults,
and threats)

Relational
aggression

An act of aggression
(physical or verbal)
intended to harm a
person’s relationship
or social standing.

(Eg. Spreading
rumors, social
exclusion)

X chromosome

X chromosome

The sex chromosome
found in males and
females. Females
typically have two X
chromosomes; males
typically have one. An
X chromosome from
each parent produces
a female child.

Y chromosome

The sex chromosome
typically found only in
males. When paired
with an X
chromosome from
the mother, it
produces a male child

Testosterone

Secreted in greater
amounts by males.

Stimulates the
growth of the male
sex organs during the
fetal period, and the
development of the
male sex
characteristics during
puberty.

Estrogens

Sex hormones, such
as estradiol, that
contribute to female
sex characteristics
and are secreted in
greater amounts by
females than by
males.

Puberty

The period of sexual
maturation, during
which a person
usually becomes
capable of
reproducing.

Primary sex
characteristics

The body structures
(ovaries, testes, and
external genitalia)
that make sexual
reproduction
possible.

Secondary sex
characteristics

Non-reproductive
sexual traits, such as
female breasts and
hips, male voice
quality, and body hair

Spermarche

A boy’s first
ejaculation, marking
the start of puberty.
Usually occurs around
ages 12-14.

Menarche

A girl’s first menstrual
period, marking the
start of puberty.
Usually occurs within
a year of age 12 ½

role

A set of expectations
(norms) about a
social position,
defining how those in
the position ought to
behave.

(Eg. A parent is
expected to nurture
and guide children

Gender role

A set of expected
behaviors, attitudes,
and traits for men
and for women.

Sexual
aggression

Any physical or verbal
behavior of a sexual
nature that is
unwanted or intended
to harm someone
physically or
emotionally. Can be
expressed as either
sexual harassment or
sexual assault.

Gender
identity

Our sense of being
male, female, neither,
or some combination
of male and female.

(Eg. binary, non-
binary, etc)

Social learning
theory

The theory that we
learn social behavior
by observing and
imitating and by
being rewarded or
punished.

(Eg. Learning
manners by
observing older
siblings or parents)

Gender typing

The acquisition of a
traditional masculine
or feminine role.

(Eg. Boys praised for
being assertive and
girls praised for being
nurturing)

Androgyny

Displaying both
traditionally masculine
and traditionally
feminine psychological
characteristics.

(Eg. Comfortable
expressing traits
culturally labeled as
“masculine” or
“feminine”

Transgender

An umbrella term
describing people
whose gender identity
or expression differs
from that associated
with their birth-
assigned sex.