The Importance of your character's backstory/history and how to share this with the reader without an info dump that stalls the action.

 Ah, yes, backstory.  My thoughts are to weave this into the first third of the novel, and of course if something later on triggers an important memory, then the author can always add a few lines of backstory.  What the writer must never do is to perform a "backstory dump," which leaves the reader with a story that has stalled if it ever got started.  

A quick example.  My character is in a new place with a new task, and a woman from her past with whom she had a love-hate relationship appears unexpectedly.  

First of all, there is some emotion, then an attempt to be cordial (she is in a public place), and then a short paragraph explaining to the person with her (and also the reader) what occured between the woman and the narrator that caused the friction. Again, make it short and enough to pique the reader's curiosity.  

Here is an example from my WIP: 

"I was seated such that I faced the windows and the hugely tempting pies case. I  couldn’t see who entered and left the room, while I watched the mountain jays hoovering up the bird seed  from the feeder, and the little birds, chickadees, I guessed,  darting  in between jay’s  visits. Charles gave a slight wave and watched someone approach our table.

            I turned to see who he greeted and froze. My heart began a frenzied pounding in my chest.

            It couldn’t be, but  it was. Her face paled as she recognized me. The “Oh Shit!” moment.

            No one had said a word. Charles looked from me to the other woman. “You two know each other?”

            “Yes,” I said, speaking quickly. “We  were journalism majors at the University of Missouri. I guess you already know Lauren Lyttle.” 

            If Lauren’s looks could kill, I would be a dead woman walking. She and I had been rivals for men and grades and then the job interviews at the university. I got the better grades and the better men, too, and had aced my job interviews. We had begun as friends until she black-balled me from her sorority. I joined another one, but she hated something about me. Maybe everything. I hadn’t thought about her for years."

    Now we know enough of the backstory to expect some conflict in the scenes to follow.  The plot advances and the backstory is just enough to fill in part of the story for the reader. And we know that more conflict is likely to occur, and want to read on.