Despite constant warnings, we are reluctant to change our ways when it comes to accumulating more and more things. We are consuming evermore energy, adding countless landfills and we buy more stuff than ever before. Why is this? The answer is our need for ownership of things. Ownership is a uniquely human pre-occupation that has its origins deeply rooted in our biology. Using fascinating examples from studies of child behavior, Bruce explains why psychological ownership is a state of mind that governs our behavior from the cradle to the grave, even when it is often irrational and destructive. A must see session for every person who cares about human behavior and how it impacts the planet.