The Big Bang Theory

The Peanut Reaction

791pages on
this wiki
The Peanut Reaction
Bbt howard
The Big Bang Theory episode
Season 1, Episode 16
May 12, 2008
Guest star(s)
Episode guide

"The Porkchop Indeterminacy"

"The Tangerine Factor"
Season guide


Season 2

"The Peanut Reaction" is the sixteenth and penultimate episode of the first season of the American sitcom The Big Bang Theory. This episode first aired on Monday, May 12, 2008.


When Penny finds out that Leonard has never had a birthday party she decides to throw him a surprise one.

Extended PlotEdit


Penny "blackmails" Sheldon into throwing a birthday party for Leonard (who's never had one before).

Peanut Reaction

Just pick one!


Happy birthday, Leonard.

The episode opens with Sheldon and Raj battling in a round of Trestling (Tetris and Arm Wrestling). But after Penny asked them to cut it out, they agree it was a stalemate. Then, Penny asked Leonard if he was going to be there on Saturday for his complimentary Birthday Cheesecake, Leonard opened up and told her that he had never celebrated his birthday because that was how he was raised; he's lactose intolerant anyway so he wouldn't be able to consume the cheesecake. Penny sympathizes with him and decides to recruit the help of the gang to throw Leonard a "Kick-Ass Surprise Birthday Party". It comes to Penny's attention that Sheldon isn't getting Leonard a present since he believes it makes no sense, but with the help of Howard, Penny was able to convince Sheldon to go buy one. Howard, who is in charge of keeping Leonard out of the apartment while the others prepare for the party, discovers Leonard obsessively playing Halo. Meanwhile, Penny and Sheldon go gift shopping for Sheldon's gift to Leonard at an electronics store. Meanwhile back at the apartment, Howard pretends to eat a Granola Bar which contains peanuts which he is allergic to, so Leonard has to drive him to the hospital. At the electronic store, Sheldon finally decides on a gift for Leonard, but as he was walking away, a woman asked him about some of the products and soon a whole line of people mistake him for one of the store's employees. Howard is now at the hospital and tries to get the nurse (credited as Althea) to give him a shot but he fails to convince her, since Leonard insists on going home as Howard's condition wasn't very serious, Howard decides to actually eat the Granola Bar with the peanuts and sure enough he was treated and was able to stall Leonard. Penny had also promised to introduce Howard to one of her sexually-easy friends. Back at the electronic store, Sheldon got chased out of the store by an actual store employee after Penny informed him about Sheldon. In the end, Leonard figured out that they were throwing him a surprise birthday party, but when he entered his house the party has already long ended. The next day, Leonard and Penny reviewed a video taken at his birthday party by Raj and by the end of it Penny kissed Leonard wishing him a "Happy Birthday". Leonard then asks Penny when her birthday was. 



Costume NotesEdit


Justice League: Star Power

S01e16 astronaut


  • This is the only episode in the entire series where a main character's birthday is celebrated. 
  • Sheldon's statement about horoscopes being hokum is based on the work of Bertram Forer, a psychologist from UCLA. His classic 1948 experiment involved administering personality tests to groups of subjects, and then giving each subject the same exact personality evaluation (copied from a newspaper astrology column) and asking them to evaluate the accuracy of the results on a scale of 1 to 5. The average accuracy was rated at an incredible 4.2, indicating that people are generally willing to accept generalized descriptions of themselves because they WANT them to be true. This experiment has been repeated hundreds of times by various researchers; always with almost exact results, giving us "The Forer Effect" or "subjective validation". 
  • As Howard attempts to remove Leonard from the apartment, in several camera angles, you can see the back of the Xbox is clearly not plugged in.
  • When Howard attempts to bribe the ER nurse, Althea, with "the man who freed your people", the bill he's offering must be one with Abraham Lincoln on it, which would be $5. Her response to his bribe indicates she'd need to see six bills with Benjamin Franklin on them to be bribed. Benjamin Franklin is on the $100 bill, so Howard is about $595 short.
  • Penny kisses Leonard.
  • The ER nurse, Althea, is the same person (or at least the same actress) as the waiting room nurse in the sperm bank from the "Pilot".
    • She is seen again in "The Robotic Manipulation", again as the ER nurse, and is again called in aid of Howard, whose robotic arm has his penis in an unyielding grasp.
    • She also appears in "The Werewolf Transformation" when Sheldon is visiting the hospital.
  • Howard`s reaction is created with clever synthetics on the actor who plays him.
  • The secret knock Sheldon demonstrates to Howard and Raj has the same pattern as the secret knock Leon teaches Mathilda in the 1994 French thriller, "Leon: The Professional".
  • Sheldon says that if Leonard was deprived of Christmas, he would be better as an experimental physicist. However, it is shown "The Maternal Congruence" that Leonard never really had fond memories of Christmas as a child either. This statement is kinda excusable due to the fact that Sheldon thinks of Leonard's Christmas to actually be fun.


Leonard : How did you know my birthday's Saturday?

Penny : I did your horoscope remember? I was going to do everybody's until Sheldon went on one of his typical psychotic rants.

Sheldon : For the record, that psychotic rant was a concise summation of the research of Bertram Forer, who, in 1948, proved conclusively through meticulously designed experiments, that astrology is nothing, but pseudo-scientific hokum.

Penny: Blah, blah, blah, a typical Taurus. So, seriously, we gonna see you Saturday?

Leonard: Uh, I don't think so.

Penny: Why not?

Leonard: I don't celebrate my birthday.

Penny: Shut up, yeah, you do.

Leonard: It's no big deal; it's just the way I was raised. My parents focused on celebrating achievements, and being expelled from a birth canal was not considered one of them.

Penny: Uh, that's so silly.

Sheldon: It's actually based on very sound theories; his mother published a paper on it.

Penny: Well what was it called, I Hate My Son and That's Why He Can't Have Cake?

Sheldon: It was obviously effective, Leonard grew up to be an experimental physicist, perhaps if she also denied him Christmas, he'd be a little better at it.

Leonard (sarcastically to Sheldon): Thank you.

Howard : Well, I love birthdays; waking up to Mom's special French Toast breakfast, wearing the birthday king crown, playing laser tag with all my friends...

Penny: Yeah! See? That's what kids should have!

Howard: Actually, that was last year.

Penny: Okay, here’s the deal, you either help me throw Leonard a birthday party or, so help me God, I will go into your bedroom and I will unbag all of your most valuable mint condition comic books. And on one of them, you won’t know which; I’ll draw a tiny happy face in ink.

Sheldon: You can’t do that, if you make a mark on a mint comic book it’s no longer mint.

Penny: Sheldon, do you understand the concept of blackmail?

Penny: Okay, how about this. You keep him there a little longer and when you get to the party I’ll point out which of my friends are easy.

Howard: Don’t toy with me, woman.

Penny: I’ve got a hot former fat girl with no self-esteem, I've got a girl who punishes her father by sleeping around and an alcoholic who’s two tequila shots away from letting you wear her like a hat.

Howard: Thy will be done. (Thinks. Reaches into back pocket, finds the half a granola bar from earlier. Looks down.) I’m doing this for you, little buddy. (Takes a bite.)

Nurse Althea: (sees Howard's peanut allergic face) Holy Crap! [Reaction]


  • Penny blackmailing Sheldon.
  • Sheldon acting as salesperson/expert.
  • It's getting worse.
  • Happy Birthday, Leonard.
  • Happy Birthday!!
  • Reminiscing about his lack of birthday parties.
  • Don't toy with me woman.
  • Leonard needs a birthday party.
  • We are doing this for him!
  • Peanut allergies.
  • Choosing present for Leonard.
  • Penny entering 4A.
  • Viewing Raj at Leonard's party.
  • How about this one?
  • You don't work here Sheldon.
  • Penny blackmailing Sheldon.
  • Chuck Lorre Productions, #210.

Around Wikia's network

Random Wiki