Both types are serious, and conscience-driven, both like to feel that they are of service, and both can be very altruistic; however, their styles and motivations differ significantly. Ones try to transcend the personal in their dealings, appealing to principles and the evident “rightness” of their positions or suggestions. Twos are highly personal and see their service in personal terms. Ones defend their autonomy–they do not want people to interfere with them. Twos seek close connection and even merging. Ones are restrained in the expression of their positive feelings although they let people know when they are dissatisfied or irritated. Twos may have difficulty with hostile or angry feelings, but they are fairly unrestrained in expressing their positive feelings.

The main difference between them can be discerned from the fact that they are in two different Triads: Ones are an instinctive type and Fives are a thinking type. While Ones certainly do think, they are primarily people of action, and are only interested in ideas that lead to some practical result. Fives, however, are truly a mental type: they can ponder any proposition or idea and do not particularly care about its practical ramifications.

Contrary to popular notions, opinions and beliefs have their basis in the instincts, in the gut. When we assert a position (“This is absolutely the way it is!”) the certainty of our view comes from our gut. If we are present enough to notice, we can feel this when we express a strong opinion. And indeed, Ones are people of strong convictions and opinions as befitting a type in the Instinctive (or Gut) Triad. Average to unhealthy Ones are entirely convinced of the rightness of their views, and respect people who hold similar strength in their convictions. They think as a way of buttressing their already established beliefs. Average to unhealthy Fives tend to get lost in a maze of uncertainty. They may develop elaborate theories or positions only to overturn them soon after. While less healthy Fives may assert provocative views, they are more interested in disturbing the certainty of others than in convincing others that they have the correct view. Unhealthy Fives may want to feel smarter than the other person, and even argue points that they do not personally agree with just to prove to themselves that they can mentally “run circles” around others. As they become less healthy, Ones become more rigid and fixed in their views about things: Fives become more uncertain, nihilistic, and afraid that they cannot arrive at any kind of meaning or truth.

Similarly, they differ most markedly in the One’s emphasis on certainty and judgment and the Five’s relative lack of certainty and difficulty with discernment. (While healthy Ones have excellent judgment, average Ones are merely judgmental–still, making judgments about the world around them is one of the principal ways in which their extroverted thinking manifests itself.) Judgment is not as centrally important to Fives. They want to understand how the world works on a theoretical level or create inner worlds of imagination that are interesting and amusing to them. Thus, Fives tend to be detached from the practical world and intensely involved with complex mental constructs. And while healthy Fives observe and interact with the real world around them, average Fives, as they become more deeply enthralled by their own cerebral landscapes, lose their capacity to make accurate assessments about the truth, significance, or accuracy of their ideas. They gradually care less about an idea’s objective rightness than about how their ideas relate to other thoughts that arise in their minds. By contrast, Ones employ thinking so that they can relate more perfectly to the world: their focus is on making rules and procedures for the progress and improvement of themselves and their world. Average Ones are not as detached from the world, or as withdrawn as average Fives are: although they may be cool and impersonal, and somewhat overly reserved, Ones are keenly interested in applying their principles to daily life.

Thus, Ones and Fives are opposites in the way they judge and evaluate reality. Ones judge situations from idealistic standards based on what they think should be the case. Fives are constantly investigating and questioning assumptions, not to mention standards and principles. Ones are deductive, operating from principles to specific applications; Fives are inductive, operating from given data to form more sweeping theories. Both are philosophical, and love knowledge: Ones as a means of perfecting the world, Fives as a way of discovering more about the world. Ones tend to be teachers and moralists, not inventors and iconoclasts like Fives. The difference between these types can be seen by comparing George Bernard Shaw (a One) and Isaac Newton (a Five), Margaret Thatcher (a One) and Susan Sontag (a Five).

Both are among the compliant types of the Enneagram. Ones are compliant to the demands of their superegos and their ideals, while Sixes are compliant to the demands of their superegos and other people, especially perceived allies or authority figures. We say that Ones have an “Inner Critic” in their heads, while Sixes have an “Inner Committee.” What these two types have in common is the tendency to feel guilty when they do something contrary either to their ideals (Ones) or to the commitments to allies, beliefs, and authorities they have made (Sixes). Guilt feelings owing to strong consciences and the tendency to strike out either at themselves or at others (or both) are the main points of similarity between them. While Sixes may rarely mistake themselves for Ones or Ones misidentify themselves as Sixes, other people may be confused by some superficial similarities between them. 

These two types are easy to distinguish, however, by noting the overall emotional tone of each type. Average Sixes are anxious, indecisive, ambivalent, and, above all, reactive. They find it difficult to relate to others with self-confidence as equals, tending either to become too dutiful and dependent or to go to the opposite extreme and become rebellious and defiant. Sometimes they get stuck in the middle and become ambivalent, indecisive, and vacillating.

These traits are almost completely absent in average Ones. Their overall emotional tone is one of self-controlled, impersonal efficiency, orderliness and propriety. Ones are emphatically not indecisive: they know their own minds and have opinions about everything, which they are more than willing to express to others. Ones are certain, and trying to convince others that they know the optimal way to do things. Sixes are uncertain, and rely on reassurance, back-up, familiar procedure, or the sanction of previously tested ideas and philosophies to help them come to decisions.

Average Ones are often so tightly self-controlled that they are able to keep their feelings at bay. They are frequently unaware of the degree of their tensions. Average Sixes struggle with more volatile feelings and have difficulty putting them aside–although they seldom express their feelings to others. Sixes carry considerable anxious tension and are more aware of it. Righteous anger, irritation, and moral indignation are the principal negative emotions in Ones, whereas fearfulness, suspicion, and anxiety are the principal negative feelings in Sixes. Moreover, while lower functioning Ones can be sarcastic and verbally abusive, they almost never let themselves get out of control and are seldom physically violent, whereas low functioning Sixes can more easily lose their tempers, sometimes erupting into hysterical reactions or even physical violence.

When it does arise, the confusion seems to stem from both types’ overactive superegos. Both are “should” and “must” people: both feel obligated to take care of all duties before relaxing or attending to their own needs. When their superegos are on more severe, both types are quite capable of telling others what to do, although in different ways and for different reasons. Ones moralize and scold, lecturing others in the name of an ideal about whatever issues are of concern to them. (“Do you have any idea how wasteful it is to use an air conditioner?”) Ones do not hesitate to order others around, telling them what they should be doing so to improve themselves or to be more effective.

Sixes can also give orders, not because of rigid inner standards, but because they are afraid of what they see as the erratic, irresponsible conduct of others potentially disrupting the security and stability they are trying to maintain. They are angered and threatened by others “breaking the rules” and becoming more unpredictable. Sixes identify with certain beliefs or authority figures and internalize the values that they have learned from these sources of guidance. Once they have identified with what they have taken to be trustworthy sources of information about the world, Sixes can be aggressive toward anyone who does not accept the same values as they do. This is especially true when Sixes are more insecure–the more anxious they are, the more they want to cling to whatever positions or allegiances they still believe in. The indifference of others to their beliefs may infuriate Sixes as much as outright rejection of them does. Compare the personalities of George Bush (a Six) and Al Gore (a One), Meryl Streep (a One) and Meg Ryan (a Six) for examples of the similarities and differences of these two types.

Ones are unlikely to mistype themselves as Sevens, but Sevens occasionally mistype themselves as Ones. Sevens who have been under stress for prolonged periods of time may notice many average One behaviors, such as perfectionism and a need for order, and conclude that they must be Ones. While these traits may surface in certain extreme circumstances, a quick review of the Seven’s life will usually reveal that rigid self-control, harsh inner criticism, and repression of impulses are not their dominant issues.

Another source of confusion is the shared idealism and sense of “mission” of the two types. Both types hold high ideals about the world and about human beings, but express these in markedly different ways. Sevens are usually very optimistic about the future and about things working out positively. Ones are far less so–they hold high standards and expect to be disappointed by people and by the world. Ones are fairly certain that they know their “mission” while for Sevens, it is more of a feeling. In Sevens, uncertainty about the nature of their mission creates a great deal of underlying anxiety. (“What if I miss my chance?”) Sevens may also think they are Ones because they see themselves as “perfectionists,” but their style of perfectionism is very different. Ones’ perfectionism drives them to berate themselves for days because they misplaced a comma in an otherwise excellent one hundred-page report. Sevens’ “perfectionism” may lead them to become frustrated because the sea food salad they ordered in a restaurant was not exactly the way they wanted it.

The two types are quite different in a number of other ways. Sevens are spontaneous and adventurous–they like to be free to change plans and to follow their inspiration. Ones get frustrated when plans are changed, and usually do not like to deviate from the careful preparations they have made. Sevens are usually unselfconscious socially, Ones are usually very self-conscious socially. Ones are methodical and sticklers for time-management and for following efficient procedures. Sevens have a more fluid sense of time, and balk at being “bogged down” by procedures. Sevens are curious and open-minded, but tend to get distracted and scattered. Ones are more focused and directed, but can be opinionated and closed-minded. Sevens are driven by anxiety: Ones by simmering anger, and so forth.

Both can be idealistic, philosophical, and somewhat withdrawn. Neither feels comfortable with their anger. Usually, the Nine’s reluctance to get into conflicts is the easiest way to discern these adjacent types. Average Nines want to maintain peace in their lives, and while they may hold strong personal convictions, they generally do not want to argue about them with people–especially people with whom they have an emotional attachment. For Ones, however, the principle is foremost, and Ones will drive home their point to convert the other to their view, even if it risks creating upsets and arguments. (“The truth is the truth.”)

While Nines can be hard workers, it does not take much to convince them that a break would be useful. They enjoy down time, and tend to have difficulty shifting gears from relaxation to activity or vice versa. Ones are extremely driven and have difficulty tearing themselves away from their various projects to take a rest or relax. They feel anxious when they are not being productive (like Threes), and want to get back to work to avoid attacks from their superego.

Another distinction can be found in how the two types handle stress. Nines initially become more emotionally disengaged and resistant, but eventually become more anxious and reactive. Ones, initially become more fervent in their efforts to convince the other that they are right, but then collapse into moodiness and a tight-lipped testiness.