 I would like to tell you how people who have feel ignored for their entire lives may become so dissolved by despair that the only thing that seems to make sense is to kill others. To understand how this might be, let's first consider an example of what it's like to be ignored. Imagine five friends having a conversation. Four of them are having a good time, but the last one feels a bit unedged. The others don't always look or answer when he or she speaks, so somehow it feels like this last person isn't even in the room like he or she has suddenly become invisible. This is basically what being ignored feels like to be invisible in the eyes of others. Now, research shows that when feeling ignored even just for a moment, people experience immediate emotional pain. They feel lonely like they are worthless or like their lives are meaningless. In fact, being ignored is sometimes referred to as social death because it makes people feel like they don't even exist. As feeling non-existing is rather unpleasant, people will try to regain the attention of others in different ways. Most are not off by being overwhelmingly nice towards others, but if this does not work, most tend to become aggressive instead. So perhaps our person ignoring conversation will get angry and start yelling at the others. This is a common response to being ignored because aggression incites a reaction from others. It incites others to see you. While it may seem a bit counter-intuitive because we'll be having aggressively rarely makes others like you, the point is a feeling invisible can be so painful that most prefer to have others look irritated at them rather than going completely unnoticed. Obviously, there's a big difference between yelling and killing. Unfortunately, most people don't get further than the point of feeling because feeling invisible is only temporary. But what if it wasn't? What if in fact you could live your whole life feeling invisible to others? What if no one ever really looked at you or answered when you spoke? What if no one ever really knew that you existed at all? Based on the findings of my PSD project so far, such a life is the reality for many of those who commit public mass murder on their own, such as lone wolf terrorists or school shooters. What happens to these people is a profound disperse that's up in them, a despair of having sung into such a low depth that they are completely unworthy of attention at all. This is why they kill because their killing makes us notice them. And so they get to escape social death. They get to exist. So will you ever ignore someone again? Fortunately, I'm not saying that we create mass murderers just because we ignore people once in a while. What I am saying is that for these people committing mass murder is a sign of a lifelong pain that no eyes have ever seen. And the question is if we can prevent such violence by paying attention to the emotional wars that are raging inside these people's minds before they get so dissolved by despair that the only thing that seems to make sense is to kill others. Thank you for your attention.