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emotions

OLogy Series
biology
card
331

emotions

OLogy Series
biology

Happy. Angry. Sad. Emotions, or feelings, tell you if something is important to you. They also tell you what your body needs and what you want to do about it. While your senses (like sight and hearing) tell you what's going on in the outside world, your emotions tell you what these things mean to you. Your emotions motivate you to do things that help you survive. Imagine if you didn’t feel basic emotions like surprise or fear!

Controlling Emotions

Part of being human is being able to control our emotions, or figure out rational ways to satisfy our urges. This kind of advanced thinking happens in our prefrontal cortex. The role of the prefrontal cortex was revealed by a shocking accident over 100 years ago..

In 1845, an explosion sent an iron rod through the front of American railroad worker Phineas Gage's brain. Gage survived, but his personality changed. Before the injury, he was polite, respectful, and hardworking. Afterward, he became impulsive, irresponsible, and rude. His prefrontal cortex could no longer control his emotional urges!

Have you ever felt the hair on your arms stand up when you're afraid? Dogs do this too. British naturalist Charles Darwin proposed that:

dogs learned this trait from humans

humans learned this trait from dogs

dogs and humans inherited this trait from a common ancestor

Are you right?

Correct!

Darwin believed this behavior evolved in an earlier mammal, to make that animal look bigger and more threatening. This is one of many ways that humans and other mammals express their emotions in similar ways. Smiling and snarling are two others.

Humans and lizards share similar brain parts. In our brain this part is sometimes called our "lizard brain." It is responsible for:

basic body functions

complex emotions

memories

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Correct!

These parts handle basic functions for survival like breathing, feeding, and defense. Lizards respond more by reflex and instinct. Mammals like us are able to have feelings like trust and anger. With these emotions mammals have more complicated behaviors and relationships with others.

Mammal brains have a thin outer layer called a cortex. In primates, the cortex has many folds and wrinkles because it's so:

large

old

soft

Are you right?

Correct!

Without these folds, the cortex would not fit inside the head! The cortex helps us control our emotions and make decisions. Primates (monkeys, apes, and humans) have an especially large cortex, which allows them to recognize facial expressions, communicate, and maintain social relationships.

All emotions are controlled by the levels of different chemicals in your brain.

Fact
or
Fiction
?

Fact

The chemicals, called neurotransmitters, send messages between brain cells and adjust how you respond to things. They help your body relax, react to danger, and feel pleasure.

Definition: how you feel about your needs, the outer world, and relationships with other living beings and things
Significance: Your emotions motivate you to do things that help you survive.
Related Brain Parts: limbic system, prefrontal cortex
Cool Fact: Instead of responding just by reflex and instinct, mammals are guided by their emotions, making their behavior more flexible.

Image credits: © AMNH.