The brain is a very complex organ. It controls and coordinates everything from the movement of your fingers to your heart rate. The brain also plays a crucial role in how you control and process your emotions.

Experts still have a lot of questions about the brain’s role in a range of emotions, but they’ve pinpointed the origins of some common ones, including fear, anger, happiness, and love.

Read on to learn more about what part of the brain controls emotions.

The limbic system is a group of interconnected structures located deep within the brain. It’s the part of the brain that’s responsible for behavioral and emotional responses.

Scientists haven’t reached an agreement about the full list of structures that make up the limbic system, but the following structures are generally accepted as part of the group:

  • Hypothalamus. In addition to controlling emotional responses, the hypothalamus is also involved in sexual responses, hormone release, and regulating body temperature.
  • Hippocampus. The hippocampus helps preserve and retrieve memories. It also plays a role in how you understand the spatial dimensions of your environment.
  • Amygdala. The amygdala helps coordinate responses to things in your environment, especially those that trigger an emotional response. This structure plays an important role in fear and anger.
  • Limbic cortex. This part contains two structures, the cingulate gyrus and the parahippocampal gyrus. Together, they impact mood, motivation, and judgement.

From a biological standpoint, fear is a very important emotion. It helps you respond appropriately to threatening situations that could harm you.

This response is generated by stimulation of the amygdala, followed by the hypothalamus. This is why some people with brain damage affecting their amygdala don’t always respond appropriately to dangerous scenarios.

When the amygdala stimulates the hypothalamus, it initiates the fight-or-flight response. The hypothalamus sends signals to the adrenal glands to produce hormones, such as adrenaline and cortisol.

As these hormones enter the bloodstream, you might notice some physical changes, such as an increase in:

  • heart rate
  • breathing rate
  • blood sugar
  • perspiration

In addition to initiating the fight-or-flight response, the amygdala also plays a role in fear learning. This refers to the process by which you develop an association between certain situations and feelings of fear.

Much like fear, anger is a response to threats or stressors in your environment. When you’re in a situation that seems dangerous and you can’t escape, you’ll likely respond with anger or aggression. You can think of the anger response and the fight as part of the fight-or-flight response.

Frustration, such as facing roadblocks while trying to achieve a goal, can also trigger the anger response.

Anger starts with the amygdala stimulating the hypothalamus, much like in the fear response. In addition, parts of the prefrontal cortex may also play a role in anger. People with damage to this area often have trouble controlling their emotions, especially anger and aggression.

Parts of the prefrontal cortex of the brain may also contribute to the regulation of an anger response. People with damage to this area of the brain sometimes have difficulty controlling their emotions, particularly anger and aggression.

Happiness refers to an overall state of well-being or satisfaction. When you feel happy, you generally have positive thoughts and feelings.

Imaging studies suggest that the happiness response originates partly in the limbic cortex. Another area called the precuneus also plays a role. The precuneus is involved in retrieving memories, maintaining your sense of self, and focusing your attention as you move about your environment.

A 2015 study found that people with larger gray matter volume in their right precuneus reported being happier. Experts think the precuneus processes certain information and converts it into feelings of happiness. For example, imagine you’ve spent a wonderful night out with someone you care about. Going forward, when you recall this experience and others like it, you may experience a feeling of happiness.

It may sound strange, but the beginnings of romantic love are associated with the stress response triggered by your hypothalamus. It makes more sense when you think about the nervous excitement or anxiety you feel while falling for someone.

As these feelings grow, the hypothalamus triggers release of other hormones, such as dopamine, oxytocin, and vasopressin.

Dopamine is associated with your body’s reward system. This helps make love a desirable feeling.

A small 2005 study showed participants a picture of someone they were romantically in love with. Then, they showed them a photo of an acquaintance. When shown a picture of someone they loved, the participants had increased activity in parts of the brain that are rich in dopamine.

Oxytocin is often referred to as the “love hormone.” This is largely because it increases when you hug someone or have an orgasm. It’s produced in the hypothalamus and released through your pituitary gland. It’s associated with social bonding as well. This is important for trust and building a relationship. It can also promote a feeling of calmness and contentment.

Vasopressin is similarly produced in your hypothalamus and released by your pituitary gland. It’s also involved in social bonding with a partner.

The brain is a complex organ that researchers are still trying to decode. But experts have identified the limbic system as one of the main parts of the brain that controls basic emotions.

As technology evolves and scientists get a better glimpse into the human mind, we’ll likely learn more about the origins of more complex emotions.