Lance Sweets is brought into the series in the fourth episode of season three ("The Secret in the Soil") as a psychologist to Seeley Booth and Temperance Brennan. His presence provides a bit of comic relief, as he is often the target of insults from both Booth and Brennan. His youth and inexperience with police work also prove to be a challenge for him, while his psychoanalysis of Booth and Brennan is typically quite accurate.
Sweets is a caring character who is well-liked, although his personality can be a contrast to the scientific, analytical personalities of the squints. He can be seen as immature sometimes, which can make his job difficult and has a habit of slipping into Valleyspeak ("totally") when under extreme pressure.
Sweets is also depicted as a skilled piano player on several occasions, although the first time his musical skills came into discussion (on the phone with Daisy), he didn't mention anything about playing piano, only saying that he played "a little bass". This is a reference to Daley playing piano in real life.
- Undergraduate - Degree in psychology from the University of Toronto
- Masters - Degree in abnormal psychology from Temple University
- Doctorate - Degrees in clinical psychology and behavioral analysis from Columbia Universityand University of Pennsylvania
It was initially learned Sweets was writing a paper on Booth and Brennan's relationship because he thinks it's not supposed to work but it does, which is why he asked them if he could continue his analysis of them. While they constantly mock him and, sometimes join together to turn against him, Booth and Brennan really understand Sweets does like them and that is why he wanted to work with them after their therapy ended - in exchange, they would have profiles. He vehemently denied emotional attachment to them, but they are all aware of the emotional connection, though they hide it with banter.
In the episode "Mayhem on the Cross", Dr. Sweets receives a review by Dr. Gordon Wyatt of his book on the relationship between Booth and Dr. Brennan. Dr. Wyatt explains he feels Sweets has misinterpreted the relationship between Booth and Brennan, mostly by looking on a somewhat superficial level. The primary focus of the work is how Booth and Brennan are opposites, yet their sexual attraction is limited due to their primary responsibility to their careers. Dr. Wyatt explains he feels Booth and Brennan are much more similar than Sweets understands, and there is an underlying sexual attraction only one of the two sees. He also tells Brennan and Booth Sweets is using his book as a way of finding his place in the world, and he has created his emotional connection with them as a way of finding a family, something Brennan compares to "imprinting" like a baby duck, though they eventually accept it. At the end of "Mayhem on a Cross" it is learned Sweets has changed the title of his work to "Bones - The Heart of the Matter," which obviously alludes to the physical bones Brennan works with, and the person Bones (Dr. Brennan) herself.
Lance Sweets is brought into the series early in the third season (episode 4 - "The Secret in the Soil") as a psychologist to Seeley Booth and Temperance Brennan. The FBI forced them to seek therapy because Booth had arrested Brennan's father and as such was considering severing their partnership before ordering the two of them to see Sweets.
Sweets's presence provides a bit of comic relief, as he is often the target of insults from both his clients, though they do show sympathy for him when he breaks up with his girlfriend (and on other occasions). His youth (according to Angela, Sweets needs to show his ID at bars to drink, and he states that he is twenty-two years old in his first appearance) and inexperience with police work also prove to be a challenge for him in the series, as many don't take him seriously (especially Booth), although his psychological analysis of Booth and Brennan is typically quite accurate. Booth is very suspicious of his ability to predict behavior using psychoanalysis, calling it "Jedi mind tricks." Although Booth grows to accept his ability and expertise at psychology throughout the show and begins to ask for his advice during interogations. Brennan is also skeptical of his ability. She calls psychology a soft science and thinks it has no credence. Both however have come to respect his ability on some level.
Despite his aptitude for behavioral analysis, he believed for a time all the members of the team hate him and find him annoying due to their behavior toward him. However, all of them have come to him for advice at least once, a fact he has to be reminded of by Cam and in the episode "The Cinderella in the Cardboard" However, Sweets seems annoyed by the fact that they always meet up with him for counseling whenever they wish instead of making an appointment or anything, basically treating him as their personal, on-call therapist. Brennan states she "likes Sweets" and can't bring herself to lie to him because she thinks she can spare him some emotional pain. Also, while able to quickly recognize when someone is lying, (Booth has described him as a "portable Polygraph",) he himself does not appear to be very good at lying; when he lied about his personal life, both Booth and Brennan were able to tell easily.
In the season 4 episode, "Double Trouble In The Panhandle," it is revealed Dr. Sweets is adopted, and his birth mother is a Psychic working in a circus in South Florida.
In the episode "Mayhem on a Cross", it is also revealed Sweets has whip scars on his back and he was, like Brennan and Booth, abused as a young child before being adopted at six years old. This is contrary to Booth's first impression of Sweets, conjecting that, based on his youth, the worst thing that ever happened that he "lost at Mortal Kombat." His loving but elderly adoptive parents died shortly before Dr. Sweets began working with Booth and Brennan, but this left him with the belief that broken people can be saved by people with good hearts, which is why he becomes a psychologist. Consequently, Dr. Wyatt proclaims he has a calling, and a good heart making him a brilliant psychologist. However, their deaths left him to figure out on his own how to transition from adolescence to adulthood without a family. He becomes close to Booth and Brennan, and, after a moment in the "Mayhem on a Cross" where they share something of their abusive past they become something of a surrogate family, hiding their emotionally close connection with banter.
"Mayhem on a Cross" also brought to light Sweets had been a fan of death metal as a teenager, and he continues to listen to it after a bad day, an additional hint his past might be more complicated than his chipper office persona suggested.
In "The Critic in the Cabernet" when Booth was in the hospital, he is visibly upset about Booth's predicament. This shows he isn't always the emotionally in control person he appears to be most of the time. Throughout season 4, Booth and Sweets's relationship has grown into something resembling that of a father-son kind of relationship, with Booth being the father-type figure.
In the season 4 finale "The End in the Beginning", he is presented as the lead singer and keyboardist of a band called "Gormogon", a reference to a character in a previous story arc. He states he "is not Gormogon" and it is simply a name. This is ironic because many fans of the show thought Sweets was Gormogon for a long time. Even in this alternate world, Booth is still a surrogate father, and Sweets is still in a relationship with Daisy. He is also protective of Brennan, having burnt evidence he thought would implicate her.
During the 7-month break between seasons 5 and 6, Sweets went on a sabbatical and took a job as a lounge pianist, even growing a beard in the process. He like the rest of the team were later called back to Washington D.C at Caroline's request to help Cam who was in trouble.
In the episode "The Shallow in the Deep", while on the party boat for "cougars" (women who like younger men), several of the women on board find Sweets attractive.
In the episode The Prince in the Plastic, Sweets got the permit to carry a firearm. Booth conducted Sweets's qualification test himself to determine if Sweets is going to be a help or hinder in the field, a test Sweets aced because from that episode onwards, Sweet is seen carrying a gun although it is not sure what his weapon is. For his examination, he uses a Smith & Wesson M&P, most likely a .40S&W version. However, it is equally possible that his sidearm is either a Glock 22 or 23, as they are the official FBI-issued handguns.
Although she thinks he shouldn't call her "Bones", according to the episode Fire in the Ice; it is shown in the episode Mayhem on a Cross that he is writing a book about Bones's behaviour and attitude, by the end of the same episode, Bones shows that she treats Sweets like a real friend, and maybe even as a part of her family.
Sweets is more like a helper for him, and always try to help him solve his problems, especially the ones involving Angela. For example, he tried to figure out what was wrong with Angela's father while he was in town to teach Hodgins a lesson in the episode The Science in the Physicists, but Sweets was unable to get any information from the girl's father.
In the episode Mayhem on a Cross, Sweets shows a great interest in Wyatt's job, and shows him that he read his book, giving the idea that he is a big fan. Although, minutes later, Sweets shows that Dr. Gordon is more like his mentor, as Wyatt not only helped Lance with his book, but also helped him with his childhood problem, by doing that, also helped a little bit more with Sweets' book about Bones' behaviour.
See also: Sweets and Daisy
In season 4, he is shown to be dating one of Dr. Temperance Brennan's interns, Daisy Wick, though he is forced to fire her on Cam's behalf. The relationship is hinted at the end of "The Man in the Outhouse," when he calls her after a session with Brennan and Booth, and confirmed at the end of "The Skull in the Sculpture". It is clear he is quite protective of her, quickly disparaging the notion he could be ashamed of her by kissing her in front of the team—something surprising them all greatly.
In one episode The Cinderella in the Cardboard, Daisy is viewed fitting a wedding dress with an unknown male by Booth and Brennan. After much deliberation, Sweets confronts her, at which point they quickly resolve the fact Daisy is not having an affair, and she was simply fitting the dress for her cousin, and the unknown male was her cousin's fiance. At that point, Daisy closes the blinds to Sweets's office and they begin disrobing as the camera pans to another point of view. In The Bones on the Blue Line, he proposed to Daisy.
Daisy's nickname for Lance is her "Sweet Lancelot"--a reference to his name, Lance Sweets, and to the romantic character, Lancelot, of Arthurian Myth.
They subsequently broke up in The Mastodon in the Room, but shortly got back together with Lance even contemplating proposing to her a second time in The Daredevil in the Mold although not going through with it.