Twins
Sandra Cortez
Psychology project MT2
Fraternal
 Fraternal twins are non-
identical twins are
formed when two egg
cells are fertilized, each
egg by a different sperm
so that two embryos are
formed are formed
 Fraternal twins can be
of the same or opposite
sex and they don’t have
to look alike
Identical
 Identical twins develop
from a single fertilized
egg that split into two
genetic replicas unlike
fraternal twins that
develop from separate
eggs and sperm
 Identical Twins can not
be different sex like there
can be with fraternal
twins
Same DNA
 Due to the fact that identical twins came from the
same fertilized egg they do have identical DNA and
they have the same blood type
 Identical twins can still end up looking different, as
they get older because of differences in diet, eating
habits, exercise, sickness etc. All of which don’t
depend on DNA and instead depend on
environmental influences.
 Having the same DNA
can sometimes become
a problem take this case
for example
 A pair of identical
twins how couldn't’t be
told apart by their DNA
were both to appear in
court for the charges of
raping a women
Fingerprints
 Many say that identical twins have everything
identical but that is false
 Even though twins share facial features and DNA
what they do not share is fingerprints
 To a standard DNA test they are indistinguishable
but any forensics expert will tell you that there is at
least one surefire way to tell them apart identical
twins do not have matching fingerprints
 Fingerprints are
influenced by random
stresses in the womb.
Even a slight different
umbilical cord length
changes the print. So far
the crime solvers
haven’t faced two
identical prints
Twin Telepathy
 Many think that all twins have twin telepathy, it is
considered as a “sixth sense” that is shared between
twins and when one twin can access the others twins
thoughts or feelings
 There has been many evidence in favor of twin
telepathy but there had also been experiments
providing evidence that there is no thing as twin
telepathy
 Stories like these give
people who believe in twin
telepathy hope in there thought
 “The identical twins who earned perfect test scores”
 “The twin mothers who gave birth on the same day”
 “The identical twins who broke the same arm on the
same day “
 “The identical twins with identical twin children”
 In 2002, a pair of seventy three year old twins was killed
on a road in Finland. There’s nothing unusual at all about
that at a first glance, until you find out that they were
killed separately, within two hours of each other. The first
of the twins was hit by a lorry and killed while he was
cycling along the road. Two hours later, his brother died
in exactly same way. To make matters even more odd,
police had not yet informed the second twin of his
brother’s death which means that he wasn’t merely trying
to follow him to the grave.
The Odds
 The chances of having
twins that are identical are
approximately 1 in 250
 It is unknown why a
fertilized egg splits to
form identical twins
 Identical twins do not run
in families and there is no
way to increase the
probability of having
them
Nature Vs. Nurture
 Identical twins share the exact same genes so some
researchers think that differences between them must be
due to the environment
 And fraternal twins have a role to play as well, even
though they don't share the same genes
 By comparing the results between fraternal twins and
identical twins, researchers can begin to determine the
meaning that nature (genes) or nurture (environment)
and if they impact on whom we are
 What is it that makes us who we really are our life
experiences or our DNA?
 Twin sisters Bernstein and Elyse Schein were both born in
New York City
 Both women were adopted as baby's and raised by loving
families. They met for the first time when they were 35
years old and found they were identical strangers Not
knowing Bernstein and Schein had been part of a secret
research project in the 1960s and 70s that separated
identical twins as infants and followed their development in
a one-of-a-kind experiment to assess the influence of nature
vs. nurture in child development
Separated at Birth
 Cases : After 39 years of being separated Jim Lewis
and Jim Springer met February 9, 1979. These twin
brothers were separated at birth being adopted by
different family’s not knowing each other both family’s
named the boys Jim. Both Jims grew up not even
knowing of each other, both had law enforcement
training, both had a passion in mechanical drawing
and carpentry. They were both married to women
named Linda who then divorced and remarried
woman with the name of Betty.
 Both had sons whom they named James Alan and the
James Allan. And they both owned dogs which they
named Toy. The twins also discovered they shared
alike habits too. Both smoked both liked beer, both
had woodworking workshops in their garages, both
drove Chevys, both had served as Sheriff's deputies in
nearby Ohio counties. They had even vacationed on
the same beach in the Florida. The same patterns
shared by the Jim Twins occurred time and time again
 This is another “separated at birth and found each
other in later life” story but with a wired ending.
These twins were separated at birth and raised by
different families. They met each other in later life,
and felt an “inevitable attraction” to one another.
They started a romantic relationship together, which
eventually led to them getting married. Soon after their
wedding, it came to light that they were in fact brother
and sister, at which point the courts ruled their
marriage invalid
Citations

BBC News. BBC, 03 June 2002. Web. 25 Oct. 2013.


"Fraternal Twins vs Identical Twins." - Difference and
Comparison. N.p., n.d. Web. 20 Oct. 2013.


"The Difference Between Identical and Fraternal Twins."
HealthyChildren.org. N.p., n.d. Web. 27 Oct. 2013.


“9 Incredible Stories about Identical Twins - The Week."
The Week. N.p., n.d. Web. 23 Oct. 2013.