Character Analysis
Poor Diane. She seems like such a rational, well put-together women, but she happens to be married to the most absent-minded mad scientist this side of Victor Frankenstein.
The Voice of Reason
We can see the difference between Diane and Wayne most embodied in their choice of careers. Wayne, as we well know, is an inventor who quit a stable job to pursue his own ambitious experiments, namely a shrink ray. You know—typical stuff.
Diane, on the other hand, is a real estate agent. This paints Wayne as an absent-minded dreamer and Diane as deeply practical, which is a dynamic we see hammered home throughout the film.
This also leads to a fair bit of conflict between the two spouses. When the film opens, Diane has left the house and is staying with her mother because, according to her daughter Amy, she "needed a rest."
We can't blame her. It's not that she doesn't believe in Wayne's abilities as a scientist—because it's obvious that she does—but simply that she refuses to accept the negative impact his obsession is having on her family.
Finally Reunited
Interestingly, it's only when Wayne's experiment goes horribly awry that the two spouses finally reexamine their problems. This disaster forces them to look closely at their individual priorities and think about how much they've let their conflict take a toll on their family as a whole, and their kids in particular.
And it's Diane that makes that realization.
DIANE: You know, it's not important if I sell another house, or if you get a grant this year or next. We've just got to get this family back together.
Now, we don't expect the Skalinskis to suddenly reach Brady Bunch levels of bliss. They've still got their fair share of issues, and we doubt that Wayne will suddenly become a responsible and sane human being. That's a bridge too far.
Still, we think that they will walk away from this experience with a greater appreciation for each other, their kids, and their wonderfully full-sized stature.