I people share content because it is a reflection of who they are. In other words, it says something about us (whether we are consciously aware of it or not). Sometimes we share helpful content because it makes us feel helpful (satisfying our need for self-actualization).
We also share emotional, attention-grabbing content, because it helps us to get noticed (satisfying our need for self-esteem). Sometimes we share opinionated content because we want to show everyone what groups we belong to (satisfying our need to belong).
When deciding what content to share, I agree with the experts, the headline says it all. The headline is what people notice first. It’s the headline that makes a piece of content stand out, get shared, and can potentially go viral.