Bernadette: I can't believe this is how you thank me.
Penny: I thanked you by thanking you. And I sent you that fancy box of pears.
Bernadette: What am I supposed to do with 20 pears? Have a pear party?

Bernadette: So what did he want?
Penny: Nothing.
Karen: He offered her a job.
Bernadette: No one likes a tattletale, Karen. So, what's up, traitor?
Penny: Dammit, Karen.

Howard: Okay, you want to engage the babies.
Sheldon: The subjects.
Howard: The babies.
Sheldon: Fine. The babies. Baby-A and Baby-B.

Howard: Engage them for a minute and take note of their reactions.
Leonard: There's something familiar about all this.
Howard: Okay, go.
Sheldon: Hello, baby. Are you having a pleasant day?
Leonard: Oh, my G-- This is my entire childhood.
Sheldon: Leonard, Leonard, you're tainting my data.
Leonard: Uh, it's like word for word.

Sheldon: Michael, you're making me look bad. Interact with me. [gasps] He grabbed my finger. Oh, he's smiling. I'm doing it.

Howard: That's time.
Sheldon: Oh, really? Can we do one more?
Howard: I think these guys need to get some food.
Sheldon: By pushing a lever at the end of an obstacle course that we design?
Howard: No, by opening the door to a hangar and letting the airplane fly in.

Amy: Although, Sheldon, maybe it could be an experiment.
Sheldon: Are you suggesting we color-code their food so we can examine their diapers later?
Amy: Sure.
Sheldon: These diapers are gonna be full of data.

Raj: I never thought I would see Sheldon enjoying himself around babies so much.
Amy: Yeah, how about that?
Raj: So he just happened to stumble upon a book about experimenting with them the same day we were hanging out with Howard's kids?
Amy: Yep, don't overthink it.

Leonard: Oh, my God. At sleepaway camp my cabin was called "Control Group."

Raj: Sheldon, he's a baby. That's not how you talk to him, okay? Just watch. [cutesy] Hey. Halley. [baby talk] Who's your favorite uncle?
Halley: [giggles] Unka Koo.
Sheldon: I got a dud, let's switch.
Amy: Keep trying. It's for science.

Penny: Hey, I thought we weren't supposed to have our phones in the booth.
Bernadette: That's a "you" rule, not a "me" rule.

Penny: Hey, can I help you?
Kwame: Actually, I'm looking for the bathroom.
Penny: Ah, yes. It's right next to the laxative booth. Clever, right?

Bernadette: Wow, we got a pretty good crowd here.
Penny: I know. But not as big as that booth. What's going on over there?
Bernadette: Yeah, that's Chantix. Ray Liotta's signing autographs until 2:00.

Danny: Is Dr. Rostenkowski around?
Penny: No, she stepped out for a call, although I wouldn't be surprised if she's in line to meet Ray Liotta.

Leonard: Hey, you guys want to make this more interesting?
Sheldon: By establishing a double-blind protocol so we have a foundation to publish? Yes.