If Tris is the ultimate Divergent, why does she lie all the time?

Question

Tris lies several times. So she's not a Candor.

But she's the ultimate Divergent.

So how to resolve that?

Answer 1

Books

Tris is indeed an unusually strong Divergent. She is not, however, the "ultimate Divergent," in the sense of having aptitude for all five factions.

A Divergent shows aptitude for two or more factions.

“Yes and no. My conclusion,” she explains, “is that you display equal aptitude for Abnegation, Dauntless, and Erudite. People who get this kind of result are…” She looks over her shoulder like she expects someone to appear behind her. “…are called…Divergent.”

We know she is not Amity.

“If you had shown an automatic distaste for the knife and selected the cheese, the simulation would have led you to a different scenario that confirmed your aptitude for Amity. That didn’t happen, which is why Amity is out.”

Nor is she Candor:

"The choices you made didn’t even allow Candor, the next possibility, to be ruled out, so I had to alter the simulation to put you on the bus. And there your insistence upon dishonesty ruled out Candor.”

Tris showed aptitude for only three factions: Abnegation, Dauntless, and Erudite.

As such, she has a greater degree of Divergence than most other Divergent, but not the maximum possible degree (i.e. equal aptitude for all five factions).

Divergence generally means greater mental flexibility, though (it’s what makes Divergents hard to control), so even a Candor-aligned Divergent could probably lie if necessary. Say a Divergent is aligned with Candor and Abnegation, and being honest would mean someone dying. A pure Candor would always tell the truth anyway. But in an Abnegation-Candor Divergent, saving the other person’s life might win out.

It’s worth noting that, despite possessing "only" three aptitudes, Tris still has a high degree of Divergence (I don’t believe that anyone with more was mentioned). As we see in the last book, she also possesses an extraordinary degree of resistance to simulations and serums, which might justify calling her "the ultimate Divergent" in another sense.

Films

Initially, the films seemed to take a similar position to the books: namely, that Tris had aptitude for three factions. From Divergent:

TRIS: No, but what was my result?

TORI: Abnegation. And Erudite. And Dauntless. Dauntless… Your results were inconclusive.

TRIS: That’s impossible. It doesn’t make any sense.

TORI: No. Not impossible. It’s just extremely rare. They call it “Divergent.”

However, it would seem that at some point, Tris having aptitude for three factions out of five was considered insufficiently heroic. As such, in the films she is the “ultimate divergent,” having aptitude for all the factions.

In order to open a box in Insurgent, Tris must also pass the Candor simulation:

TRIS: Mom, I don’t want to be Divergent anymore. I just want to feel safe again.

VO: Candor sim complete.

As well as the Amity simulation:

SIMULATION TRIS: No one’s gonna love you Tris. They’re not even gonna miss you. This world will only be better off without you. One less Divergent ruining things. And no one will ever forgive you for what you’ve done.

TRIS: You’re wrong. Because I will.

VO: Amity sim complete.

The basic explanation for why she could lie, though, remains the same. Why could she lie despite her capacity for Candor? Why was she able to fight and kill people if she had aptitude for Amity?

Being Divergent means being not being bound by the mental restrictions of factions. While in the books, Tris’s performance in her initial simulation would have indicated that she was not suited for Candor, in the movies it’s more clear that Divergence represents the capability to act like one of the factions, not the obligation to do so. In other words, Tris has both Amity and Dauntless in her, but can act in an Amity or Dauntless manner, depending on the circumstances. Think of Tris’s brain as a computer that can boot multiple operating systems. As mentioned earlier, if Tris is faced with a choice between lying and saving someone’s life, her Dauntless and Abnegation tendencies might overrule her Candor tendencies, and thus push her to conceal the truth.

In the films, the point of being Divergent is greater mental flexibility. Leaning toward Candor might mean that she has some tendency to be truthful, but could break that mold if necessary—say, if her other factional tendencies are stronger in a given situation.

Answer 2

Tris is 100% divergent. Meaning she is equally all of the factors. It's not about if she does it, it's about her ability to do it. Remember, some factors intersect such as dauntless and amity. Meaning she can't be all of them at the same time. You also have to remember the test that decides your faction is basically a personality test. As the last movie shows, though Tris has the ability to be amity, all of the things happening to and around her, makes her a little on edge and emotionally unstable as you could see when she failed the amity test due to the lady talking about her newly passed mother. The second time around, Tris had to fight herself. Fighting her own emotions and thoughts. Even her own self got under her skin a little when she finally pushed her back. But at the end of the fight, Tris forgives herself and finds her inner Amity balance, completing the sim. Hope this helped!