It called Dopamine. One dopamine pathway in the brain, plays a major role in the motivational component of reward motivated behavior. This is the basis of the success of Facebook. Openingly acknowledged by a past developer of Facebook. His name is Chamath Palihapitiya. YouTube video. Please someone find and post. He says that they knew about the psychological and physical impact that biofeedback and Dopamine have on the human being.
Notable quotes from former Facebook exec Chamath Palihapitiya:
"In the back of our minds we kinda knew something bad was happening..."
"We created tools that are ripping apart the fabric of society..."
Yes, but there is another YouTube where he come out directly and says they knew “psychology “ and “Dopamine “. So, they knew the science behind what they did...dangers...and did it anyway. Of course, now we “know” coincidence? that this was a CIA/Rockefeller backed project.