Our brains are prediction machines. They constantly process incoming information and assess how it matches its own expectation models. With several end goals (many we are not actively conscious of like security, food, status, and reproduction) the brain makes sense of our environment and directs our behaviors, thoughts and emotions. This is where the concept of psychological entropy comes in. Entropy is a measure of disorder in systems; many of us first learned of entropy in relations to physical systems like ecology and physics. The same principles of entropy apply to all information-processing systems (this includes our nervous, immune, and psychological systems). All biological organisms (including you and I) survive so long as we are able to manage internal entropy. Our brains develop strategies to minimize entropy and restore balance. Like all antifragile systems, a certain degree of stress and unpredictability is healthy but persistent chaos can have detrimental effects.
So what does any of this have to do with consumer social tech? Most successful social products start simple. The best remain so while the rest become chaos as they scale. Think about how exhausting Facebook feels lately. As social creatures there are some core fears we have and our brains are constantly building prediction models for: fear of failure, fear of rejection, fear of losing control, fear of losing status/reputation, and fear of losing emotional connection. Products that overwhelm our prediction models are bound to earn our distrust.
For the builders our there: optimize for simplicity, minimize psychological entropy, and as I wrote last week, encourage cooperation.