Dopamine

Dopamine is a neurochemical, that works in animal brains to incentivise them to do stuff (Figure 1).

Figure 1. Dopamine is not the goal. Dopamine release causes the progression to a goal.

Figure 2. Dopamine release curve.

Figure 3. Dopamine in action

When your dog sees a ball you are about to throw it causes dopamine to be released which causes a type of craving to for the ball. This means dopamine is not so mush the actual reward but more the incentiviser. The release of dopamine only occurs in the wanting stage (see Figure 2), i.e. between seeing the ball (signal) and actually getting it (reward).

This process is addictive, once complete, the dog looks for its next trigger, that starts the dopamine release again (Figure 3). This process could proceed infinitely however within every cycle is a downward step, a negative feedback loop, which means everytime the dog runs and gets the ball its reserve energy reduces a notch and eventually the dog tiredness overcomes the want for another reward and it stops.

Greed

This is a very simplified way of seeing motivation, in humans there are often a lot more nuanced requirements to generate a dopamine release pathway. However, the general dynamic often stays the same.

Loop	Expended energy	Remaining Energy
Rest	0	5
1. Signal>Work>Reward	-1	4
2. Signal>Work>Reward	-1	3
3. Signal>Work>Reward	-1	2
4. Signal>Work>Reward	-1	1
Rest	0	0

Every negative loop, goes to a lower level and acts as a self controlling mechanisms to stop the process from getting out of control. However, there are some loops, which are specific to humans which do not have a self controlling mechanism, these were identified by Bertrand Russell

Acquisitiveness

Rivalry

Vanity, and love of power

The main difference between humans and a dog in is that you can perform longer loops as opposed to shorter loops due to your neocortex having the ability to discern time. This is called the Curse of Sisyphus, dopamine far from being the reward molecule is actually the greed molecule.

Reference