While science has identified hundreds of different neurotransmitters in our brains, there are five that are most commonly identified with behaviour. Each of these are part of our survival mechanism and will encourage or discourage specific behaviours with the goal of keeping us safe.

1. Dopamine
2. Oxytocin
3. Serotonin
4. Endorphine
5. Cortisol

Dopamine, oxytocin, serotonin and endorphine are often collectively referred to as the “happy chemicals”¹. They make us feel good in different ways and have evolved to encourage us to do those things that promote survival.

Cortisol, often called the stress chemical, is the opposite. It makes us feel awful and acts to drive us away from actions that would impact our survival.

Dopamine

Dopamine is that reward for doing something. When we check something off our todo list, we get a hit of dopamine.

Note that we get that dopamine for taking any step, whether or not that step actually moves us forward. Our brain is rewarding the fact that we took action only and is not making any judgement on whether the action was positive. This sometimes leads to the wrong behaviours as we’re getting rewarded for being busy, not being effective.

We also get dopamine for successfully predicting actions that will come. Our brains prediction engine is constantly recalibrating itself to ensure that it’s successfully able to anticipate dangers. Whenever it makes a successful prediction, we get a hit of dopamine. The millennial whoop is a fun example of dopamine used to tune our prediction engine. As we successfully predict the music to come, we get a steady stream of dopamine.

See also: Researchers have found multiple types of dopamine neurons with different functions

Oxytocin

Oxytocin motivates you to find safety in companionship. It encourages us to work together with others. When we trust someone or they trust us, oxytocin is flowing.

It’s stimulated by touch and by trust. Within a team that’s truly collaborating then oxytocin will be constantly flowing.

Interestingly oxytocin works both ways. It flows when we trust others and also when others trust us.

Oxytocin has the effect of suppressing the activity of the amygdala², which reduces anxiety and stress.

Serotonin

Serotonin is a reward for gaining the respect of others, which in turn helps our survival chances. It’s sometimes refered to as the leadership chemical.

If I help someone across the street, I get a shot of serotonin. If you then witness me helping someone across the street, you also get a shot of serotonin.

All living creatures have serotonin, even plants and amoeba.

Mammals also get serotonin when they have secure access to food or other resources.

Endorphine

Endorphine masks pain so you can escape from danger when you’re injured. Our brains release endorphin as soon as it thinks we’re likely to be injured which can have the unintended side effect of encouraging risky behaviour.

For people who parachute, the moment they throw themselves out of the plane, their brain predicts that they’re about to suffer significant injury and so it releases a flood of endorphine which causes that feeling of euphoria. Anything that releases endorphines will cause a natural “high” sensation.

Laughing and crying both cause convulsions that trigger endorphines. Have you ever laughed so hard that after a while your stomach started to hurt? It was hurting right from the beginning but you didn’t feel it until the endorphine wore off.

Cortisol

Cortisol communicates pain and the expectation of pain. It motivates us to do whatever it takes to remove the threat.

If our social standing is threatened in any way, cortisol will start to flow. Reduced social standing reduces our chances of survival.

Elevated cortisol levels impair performance on memory tasks that depend on the hippocampus.²

While helpful in a short term survival situation, cortisol has many negative side effects over the long term. It suppresses the immune system, increases both blood pressure and blood sugar levels, and decreases learning ability³.

In better news, mindfulness has been shown to lower cortisol levels² as has laughter, regularly walking in nature, visual art, and the power pose. See the anti-anxiety toolkit for more on each of these.

Summary

In summary, these neurotransmitters can have powerful effects on behavior, influencing motivation, pleasure, social bonding, mood, pain, and stress responses. Understanding the role of these neurotransmitters can help individuals better understand their own behavior and develop strategies to optimize their mental and emotional well-being.