|What makes you yourself? How you are unique from
others? Because of your body, mind or memory?|
|Question Date: 2017-11-22|
That's a profound question. It's more of a
philosophy question because "self" doesn't really
have a scientific definition. Science is a
powerful way of understanding the world, but there
are some kinds of questions it can't answer.
I can say a bit about the brain, memories, and
personality. We know that damage to certain parts
of the brain, due to illness or injury, can change
a person's personality and take away their
memories. One famous example is a case of a
railroad worker in the mid-1800s. He was using a
long iron rod to pack explosive powder into a hole
and the powder went off, driving the rod through
the man's face and destroying most of the left
frontal part of his brain (here's his story
neurosciences and story ). He had been a nice
guy who was easy to get along with, but the injury
seemed to change him to a bad-tempered guy who
just wasn't the same person, according to his
Diseases like Alzheimer's can steal a
memory and cause people who have been confident
and trusting into suspicious, fearful people who
think their loved ones are trying to harm them.
Sometimes people with brain damage will have good
days, when they seem more "themselves." So perhaps
there is a part of their personality that is still
So what do you think? How might the answer
influence medical or legal decisions? If this
kind of question interests you, you may want to
study the philosophy of science.
Thanks for asking,
That is an interesting question Vishnav, and
likely has different answers depending on who you
ask. As individuals we all have different bodies
and brains. Even identical twins, while they have
the same DNA, have different experiences that lead
to different memories. So I would say all three
things make us individuals.
How do WE know we are individuals?
Cognitive neuroscientist are trying to understand
the regions of the brain that give us the sense of
“self”. These studies are very interesting
but something I know little about! Here is a link
to a Wikipedia page that you may find helpful.
neural basis of self
The answer is "yes", all of them (body, mind,
memory)make you yourself. No two humans are
completely alike genetically (not even identical
twins, thanks to mutation). On top of that,
you have different experiences and memories. All
of these things contribute to who you are.
I believe that it is still actively debated what
the relative importance of these different factors
Your genes make you different from anyone
else. You get the half the DNA in your genes
from your mother and half from your father, and
with each parent giving you 3 billion base pairs
of DNA, there's no way you share all of them with
anyone else, unless you're an identical twin.
Then the environment makes each of them
slightly different. The environment can even
change our genes, in a process called
'epigenetics,' where -CH3 methyl groups and
other little things are added to a few of the DNA
bases, which does things like turning genes on or
Here's google's first answer to your question,
by someone who has thought about the question more
deeply than I have:
what makes you you
This guy writes entertaining posts. If you go to
the end, you'll find links to other people who
have thought seriously about the question.
There's a Psychology Today blog, it says your
memories make you who you are. I'll argue that
this is only part of the answer!
There are other interesting hits, if you just
paste your entire question into a google search;
but I'll let you find them for yourself.
A useful analogy may be to consider a
snowflake. Every snowflake is made up of water
molecules, which obey the same laws of physics and
chemistry such that under the right conditions
they spontaneously form into a self-organized
structure, a snowflake. However, every snowflake
is unique and different due to slight,
imperceptible variations in the initial
Similarly, every person is made up of cells,
which are made up of atoms, which obey the same
laws of physics and chemistry. During
development certain genes are switched on and
signal certain cells to differentiate and form
organs. Some cells will differentiate to become
neurons, which subsequently form electrochemical
connections with other neurons in the brain.
Ultimately the millions of neural connections
gives rise to consciousness. Even though we are
all made up of the same biological material, every
person is unique (including identical twins who
have the same genetic makeup) because of subtle
variations that occur during development and on
into life. In physics this processes is
called emergence (
emergence ), which is the theory that
describes how the constituent parts of complex
systems interact to form phenomena that emerge at
the level of the whole.
The science of emergent phenomena was
explicated by Philip Anderson in a 1972 article,
“More is Different. (
more is different ).
Consciousness is one example of emergence
arises spontaneously due to the millions of
interactions of individual neurons. To a large
extent, who you are is a result of the sum total
of these millions of complex interactions.
However, on an even larger scale individual humans
interact to form self-organized systems such as
economies, cities, and culture. So, who you are is
also a product of the culture in which you live.
Thanks for the great question.
Scientists have identified three different, but
related, reasons why each person is unique:
genes, how those genes interact with different
environments, and noise / personal experiences.
First of all, differences in genes can
explain differences in people , sometimes in
dramatic ways – for instance the presence of
certain genes on the Y-chromosome determines if
you have a male physiology. Differences in other
sets of genes cause other differences that we see
among people, including the color of their hair
and eyes and how tall they can grow. In fact,
every single human (putting aside identical twins)
has a unique combination of genes that has never
existed before and will never exist again. That’s
Despite this, humans actually have a very high
degree of regularities between them. For instance,
nearly everyone’s heart is designed the same way
and has the same function. If you opened an
anatomy textbook from hundreds of years ago, you
could still learn about the correct shape of the
heart. So where do other changes come from if
not just the genes?
Some features that differ between people are
the product of facultative adaptations.
This refers to genes that react to the environment
in ways that help the organism survive. One
example is the way skin tans. When exposed to lots
of sunlight, genes that control your skin cells
react by producing more melanin, toning the
skin darker to protect the cells against intense
sunlight. So facultative adaptations, the
interaction of certain environments and certain
genes, also explain differences between people.
A last important factor we can call noise or
personal experiences. These are all the
events that happen across a single lifetime that
also make you unique. For instance, you could go
to the gym a lot and gain muscle, or you might get
a haircut. Such experiences, again, make each
person unique, and influence who we are. Note,
however, each factor affects every other factor
– who we are is a very complicated story!
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