Page 206 - Ray Dalio - Principles

neurons. Given billions of neurons, this means that there are as many connections in a
single cubic centimeter of brain tissue as there are stars in the Milky Way galaxy.

When we are born our brains are preprogrammed with learning accumulated over hundreds
of millions of years. For example, researchers at the University of Virginia have shown that
while many people have an instinctual fear of snakes, no one has an instinctual fear of flowers.
The brains that we were born with had learned that snakes are dangerous and flowers are not.
There’s a reason for that.
There is one grand design for the brains of all mammals, fish, birds, amphibians, and
reptiles, which was established nearly 300 million years ago and has been evolving ever since.
Just as cars have evolved into different versions—sedans, SUVs, sports cars, etc.—that rely on
many of the same underlying parts, all vertebrate brains have similar parts that do similar
things but that are well adapted to the needs of their own particular species. For example, birds
have superior occipital lobes because they need to spot prey (and predators) from great heights.
While we humans think of ourselves as superior overall because we overemphasize the
importance of our own advantages, other species could justifiably make the same claims on
their own behalf—birds for flight, eyesight, and instinctual magnetic navigation; most animals
for smell; and several for appearing to have particularly enjoyable sex.

This “universal brain” has evolved from the bottom up, meaning that its lower parts are
evolutionarily the oldest and the top parts are the newest. The brainstem controls the
subconscious processes that keep us and other species alive—heartbeat, breathing, nervous
system, and our degree of arousal and alertness. The next layer up, the cerebellum, gives us the
ability to control our limb movements by coordinating sensory input with our muscles. Then
comes the cerebrum, which includes the basal ganglia (which controls habit) and other parts of
the limbic system (which controls emotional responses and some movement) and the cerebral
cortex (which is where our memories, thoughts, and sense of consciousness reside). The
newest and most advanced part of the cortex, that wrinkled mass of gray matter that looks like
a bunch of intestines, is called the neocortex, which is where learning, planning, imagination,
and other higher-level thoughts come from. It accounts for a significantly higher ratio of the
brain’s gray matter than is found in the brains of other species.

4.2 Meaningful work and meaningful relationships aren’t
just nice things we chose for ourselves—they are
genetically programmed into us.