I wrote about toxic assumptions back in 2009. It's a term I rather like, but I've got a better definition of it now. Toxic assumptions are the kind of presumptions that are deeply embedded within companies but which contribute toward innovation inertia. They are the assumptions that commonly go unchallenged, and are typically based on a view of the world that relies on existing market, model or competitive dynamics. As soon as those dynamics change, potentially in unforeseen ways, the business is underprepared and struggles to adapt.