AMY: Mom and Dad had an argument last night and Mom spent the night at Grandma's. I think she just needed a rest.
This is our introduction to the Szalinski family. They don't exactly sound like the Bradys, huh? As we learn over the course of the movie, Diane Szalinski has plenty of reason to be exhausted by her mile-a-minute madman of a husband.
NICK: Look, I finished mine. It looks just like yours, huh?
WAYNE: Nick, I've got to get this working before I leave. Why don't you go help your sister?
Young Nick looks up to his father a great deal, modeling himself after Wayne's mad scientist ways. Unfortunately, Wayne is too focused on his own experimentation to give his son the time of day, which creates a rift in their relationship. That's a real bummer.
BIG RUSS: There's a big fish out there with your name on it.
LITTLE RUSS: Fishing's your thing, Dad, not mine.
Unlike Wayne, Big Russ Thompson wishes that Russ Jr. wanted to be more like him—an athlete and alpha male extraordinaire. This leads to a lot of deep-seated conflict between the two.
AMY: Dad, don't forget my dress from the cleaners, Nick's allergy pills…
WAYNE: It's all in my head, don't worry.
Are you sure about that, Wayne? As he proves time and time again, the Szalinski patriarch is too absent-minded to give his kids—or his wife, for that matter—the attention they deserve.
RON: Hey Dad, want to go play some baseball?
BIG RUSS: Baseball? No.
Although Big Russ gets upset when Little Russ refuses to follow in his sports-worshipping footsteps, he totally denies his son Ron when he tries to do the same. What's up with that?
DIANE: I sold a house [...] The Boorsteins bought it. I only had to show it to them twelve times.
Unlike her perpetually frazzled husband, Diane Szalinski is decidedly practical. We see that in her choice of career: real estate is a much more reliable source of income than pseudoscientific tomfoolery.
DIANE: Where are the kids?
WAYNE: I haven't seen them since this morning.
If you were looking for evidence that Wayne isn't the most present father in the world, then consider this your smoking gun. Wouldn't you expect him to be a little more concerned about the sudden disappearance of his children?
POLICE OFFICER: This sort of thing happens all of the time. You have a little spat with the kids…
BIG RUSS: Whoa. We did not have a spat.
We could write a book about all of Big Russ' failings as a father, but problemo numero uno is that he refuses to acknowledge any of them. This makes everything so much worse because his kids don't just feel pushed around by their old man—they feel ignored by him.
BIG RUSS: What do you mean he was afraid to tell me? He could tell me anything he wants. You know me. I always listen.
This statement is dripping with so much irony that you could fill an Olympic-sized swimming pool with it. Although the whole "shrunk kids" experience opens his eyes to his failings as a father, Big Russ is oblivious to his sons' feelings for the bulk of the movie.
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.
In another lovely bit of irony, Wayne and Diane only manage to get their marriage back on track by losing their kids. The experience reminds them of the importance of family and highlights their own individual failings at keeping said family together. It might not be pretty, but it does the trick.