This leads to a feature of our dopamine neurons which are taken advantage of by casinos and social media sites the same. This is called "Dopamine reward prediction error coding" (Schultz 1). To explain this I'll use slot machines as an analogy. When you play slots, the time between pulling the lever and finding out the result gives your brain time for the dopamine receptors to become active, making the game feel rewarding by just playing. But if you keep losing, your brain stops releasing dopamine, and you might not want to play anymore. So, casinos need to make sure there's a mix of winning and losing to keep people interested. This is similar to getting notifications on your phone. As long as enough of the notifications are positive social stimuli, you will be excited to see whatever notification you get next. Even though most notifications are not insanely exciting or are not positive stimuli, because of the low cost of checking our phones, we often check them anyway. Programmers for these social media sites know these things, and design their platforms taking full advantage of them.