Q. My boss tends to say "no" to most suggestions or requests I make. I've never thought of her as particularly negative or vindictive but this is getting ridiculous. I'm curious to know if you think this is a "brain thing."
A. The simplistic answer is, yes, since everything begins and ends in the brain. A more helpful response, perhaps, is much more complex. Some people have a great need to feel powerful and important. Depending on what else is going on in their lives, they may achieve this temporary and fleeting sense of power primarily when they say "no."
The "terrible twos" so called, describe a period of time when children are beginning the process of individuation. If they live in an environment in which they have few choices, the fastest way to begin feeling autonomous is by saying "no," because there's so little opportunity to make choices.
I see this in adults, as well. Unfortunately, sometimes among females in positions of power. This can be exacerbated when the females have felt powerless, comparatively speaking, much of their lives. When they say "yes" to another's ideas, they perceive that as being powerless (e.g., just going along with someone else's choice). In the other hand, when they say "no," this gives them a temporarily perception of being in charge and feeling more powerful. Unfortunately, they often cut off their nose to spite their face because sometimes they say "no" when it would be so much more functional and effective to say "yes."
Sometimes I've been able to work around this stance by proposing the opposite of what I believe should be done. The response is typically "no." So then we explore opposite possibilities, which is what I had hoped for all along. This has to be done very carefully because you want to avoid becoming a manipulator of sorts.
Remember, the typical human brain has two hemispheres—a right and a left. And the pre-frontal cortex is designed to make choices. Many caregivers fall off one side of life's proverbial highway but failing to give children choices; others tip over the other side by allowing for too many choices. Current wisdom is to deal with only two options at a time. If you try to juggle three or more, the brain will "discard" everything but two and concentrate on those two. I try to work options two at a time until I come to my most-preferred two, and then select from those.