Keep Your Protagonist's Growth Authentic

We all know that an engaging external plot can keep readers turning pages. But what about the internal plot of your manuscript? Because in a whole lot of great novels, the protagonist we start with is NOT the one we end with. The external journey they've taken will fundamentally change something about them~ their perspective, their heart, their confidence level, etc.

EXTERNAL EVENTS affect INTERNAL CHARACTERISTICS~ that kind of thing.

Yesterday I was taking a few goofy photos of my daughter and the matter of authenticity sprang to mind. Here is my daughter's hair shortly after birth (about 5 weeks ago):

And here are two pictures of it yesterday:

Most readers can spot a contrived external plot and critique partners/beta readers will generally point those out for you.

Okay, okay, so I faked it.

But the internal plot is something you, as the writer, really need to consider in terms of 
what you want your character to do internally with the external plot elements you hand him.
How do you want him to change because of the experiences you've put him through?

Today I challenge you to take a look at your current manuscript and see whether or not your character has internally changed and if that change is authentic, having gradually built on all of the external factors that you've presented to the reader.

(And I also challenge you to take goofy pictures of your children/spouse/pet/self~ it's a great way to spend a few minutes...until someone walks in the kitchen and says, "Um, what are you doing with the baby?" Then it gets a little awkward)