2. Heredity
Gene – Basic unit of heredity
Chromosome – A string of many genes
Mutations – Chemical change in genes
Dominant – Gene whose effect is noticed when
combined with any other gene
Recessive – Gene that will manifest itself only
when paired with a similar gene
Autosomes – The chromosomes that are alike in
both the male and female
Deoxyribonucleic acid (DNA) – Chemical
composing a human chromosome.
3. Sibling Relationships
Siblings – people who have the same parents.
Many siblings have close relationships while
growing up, they’ve shared many of the same
experiences.
Relationships among siblings are affect by
many factors and are unique:
Location
Parent
Multiple siblings
4. Single-Parent: Family Structure
In a single-parent
family, the parent has
many responsibilities.
The amount of time
the single parent can
spend with his or her
children may be
limited.
Siblings in this family
structure may form
close relationships.
5. Stepfamily: Family Structure
When a single parent
remarries, the few
stepfamily often includes
stepsiblings.
Stepsiblings – a
stepparent’s child from a
former marriage.
Relationships among
stepsiblings may be
strained at first.
A stepsibling can be a built-
in friend.
6. Stepfamilies: Family Structure
Many stepfamilies
include half
siblings.
Half siblings – a
sibling who has
only one parent in
common with a
brother or sister.
7. Family Size
Family size can affect
relationships between
siblings.
In smaller
families, children may be
together often and in so
form close bonds.
In larger families, children
are likely to spend more
time with siblings about
their age.
8. Spacing Between Siblings
Spacing refers to the number of years between
children in a family.
The bonds between siblings can be affected by
spacing.
Siblings who are close in age may have a lot in
common however, these siblings are more likely
to compete with each other creating rivalry which
prevents the siblings from being close.
Siblings who are spaced more than 6 years apart
may be treated almost like only children. They
may have few shared interests because of the
large age difference.
9. Sibling Gender
Gender – Sex as a male or
female.
Sex Role – The way a
person is expected to act
based on his or her sex.
Girls tend to imitate the
female sex roles they see
their mothers model.
Boys tend to copy the male
sex roles they see their
fathers model.
10. Sibling Vocabulary Terms
Role – A socially expected behavior pattern.
Peer Group – People of about your own age.
Authority Figures – People who make final
decisions.
Culture – The total social environment of a
people or group.
Peer Pressure – The influence exerted on a
person by other people in his or her age group.
11. Birth Order
Birth Order – A child’s place in
relation to other children in the
family.
It has an effect on personality
as well as on sibling
relationships.
Firstborn, middle, and
youngest children may not be
treated the same by their
family members.
12. Firstborn Child
The firstborn child has a unique place in the
family.
For a while, a firstborn child is an only child.
Parents are often eager to see their firstborn
child grow up. They may push the child to
learn new skills.
Independence and self-confidence may
prompt firstborn children to be leaders in their
families.
Because these children grow up first, they may
be given more responsibilities.
13. Youngest Child
The youngest child in a family often receives
care from older siblings as well as from
parents.
A youngest child often learns to talk and get
along with people at an earlier age than other
children.
In some families, parents and older siblings
routinely make decisions for the youngest
child.
This may cause the youngest child to be less
independent than older siblings.
14. Middle Child
A middle child is neither the youngest nor the
oldest.
While all the children are living at
home, middle children sometimes feel left out.
Feeling left out may cause middle children to
work harder.
They might become good students or show
talent in music or a sport.
Middle children often become peacemakers
among their friends and family members.
15. Only Child
The only child has no siblings.
Some of these children may feel lonely.
However, many only children enjoy growing up
alone.
Only children seem to learn quickly.
Because of all the attention and help to
succeed, most only children form strong self-
images.
Only children must learn how to get along with
others by spending time with friends.
16. Twins
Twins have a special kind of
sibling bond. They are born at
the same time.
Identical Twins – Siblings born
at the same time who inherit
the same set of characteristics
from their parents.
Fraternal Twins – Siblings born
at the same time who do not
inherit the same set of
characteristics from their
17. Twins
Even thought twins may look and act alike, each twin
is a unique person.
Each has his or her own needs, wants, and goals.
Parents, siblings, friends, and teachers need to
remember to treat twins as individuals.
Identical twins do not have the same fingerprints.
18. Multiple Births
When a mother has…
– Three infants at the
Triplets
same time.
Quadtruplets – Four infants at the
same time.
Quintuplets – Five infants at the
same time.
Septuplets – Six infants at the
same time.
Septuplets – Seven infants at the
same time.
Octuplets – Eight infants at the
same time.
19. Sibling Rivalry
Sibling rivalry –
Competition between
brothers and sisters.
Rivalry often begins
when a new baby
arrives.
Some children resent
the extra attention
given to special
siblings.
