A paper from Cornell University attempts to explain why businesses claim to applaud creativity, but actually may hold a bias against creative ideas, leading to an environment in which innovation and creativity can be stifled. 

The authors point to two different studies that find that many people hold a distinct bias against creative ideas, even while supporting the concept of creativity in general. This unconscious bias is one that people don't want to admit, like many unpopular biases. 

Uncertainty about new ideas tends to make people uncomfortable, feeding this bias. When looking at a new and novel approach to a challenge, many people will fall back on a "tried and true" (but possibly less effective) solution. 

So when asking for "out of the box" PR ideas, relax, open up and be prepared to accept them!