On this week’s Big Bang Theory - The Emotion Detection Automation, Sheldon gets himself an experimental device from MIT that will help recognize people’s emotions. The group suggests that Sheldon try this contraption out after he was insensitive to Raj’s recent break-up. The device works great, but it causes some trouble.
Penny tells Leonard that she got her brother an interview at her job, so he will be staying with them. Leonard hides his feelings to Penny, but it is clear he isn’t too excited about this. He doesn’t even think her brother would get the job due to his criminal record. When Sheldon walks into the conversation with his new device, he is able to tell that Leonard is angry about the visit.
Leonard admits that he is upset that she didn’t ask him first. Penny didn’t think that it was a big deal since it is her brother. Leonard however, thinks that if he gets a job, he will be living there with them. Penny argues saying he would get his own place and it wouldn’t be any different than Leonard making her live with Sheldon. This insults Sheldon but Leonard tells him to stay out of the argument, pointing out that his machine started it.
Later, Amy finds Sheldon upset in their rooms. He is upset that he tried the machine. He said it made him realize just how bad he is at recognizing emotions. Amy comforts him and says that he has gotten a lot better since she met him. She says she is proud of him.
Leonard and Penny eventually apologize to Sheldon. Leonard says that Penny is going to tell her dad that it isn’t the best time for her brother to stay with them. Penny then reveals that she is planning on throwing Leonard under the bus by telling her dad that he doesn’t want him there.
In tonight’s sub plot, Raj wonders if the MIT machine would help him figure out why women keep dumping him. Raj jokingly suggests that he sends them all a survey card. Raj takes his idea seriously and takes it a step further. He decides to get them all together for a focus group. Howard thinks it is a horrible idea, telling him he will just get hurt.
Raj goes ahead and gathers four of his ex-girlfriends: Lucy, Claire and the two Emilys. They take turns explaining why they broke up with Raj. Reasons include Raj being a needy narcissistic mommy’s boy. All of them reveal that after Raj, they moved onto better relationships. Howard stands up for Raj, saying he is brave and he is just trying to better himself. Raj’s most recent ex, Emily, says she is surprised that Howard and Raj didn’t end up together. The two of them joke about what it would be like being a couple and Raj starts to nag Howard about his health.