Keirsey takes the 16 MBTI types and places them into four groups of people, believing that the people in these groups share similar mindsets. These groups are:

The Guardians – ESFJ, ESTJ, ISFJ, ISTJ.

The Artisans – ESFP, ESTP, ISFP, ISTP.

The Rationals – ENTP, ENTJ, INTP, INTJ.

The Idealists – ENFP, ENFJ, INFP, INFJ.

From what I have understood about the cognitive functions, I don’t see why these groupings would be in existence. I especially don’t understand how types who share zero functions, i.e. the NT’s, and NF’s would share a similar mindset.

Why wouldn’t you place those who share the same judging, and perceiving functions into the same groupings? When you think about it, these types would hold similar values even if their priorities are flipped, so to say.

This is where Socionics Quadras got it right, and MBTI got it wrong. The quadras are:

Alphas – ENTP, ESFJ, INTP, ISFJ.

Judging Functions: Fe, Ti Perceiving Functions: Ne, Si.

Typical Alpha quadra group behavior: Spontaneous, disorganized activities “for the fun of it.” Light-hearted, non-serious atmosphere with very few “heavy” moments. Skipping from topic to topic without focusing on the implementation of conclusions reached. More

Beta – ESTP, ENFJ, ISTP, INFJ.

Judging Functions: Fe Ti Perceiving Functions: Se, Ni

Typical Beta quadra group behavior: Lengthy, theatrical monologues. Loud, hearty laughter. Importance given to group rituals such as those related to food and drink. Displays of great generosity and inclusion, but with the demand of emotional involvement in group. Rowdiness. Generally theatrical atmosphere, but with periodic moments of “dead seriousness.” More

Gamma – ESFP, ENTJ, ISFP, INTJ

Judging Functions: Fi Te Perceiving Functions: Se, Ni

Typical Gamma quadra group behavior:

Trading jokes on materialistic topics (money, sex, winning and losing). Rowdiness and drivenness. Prefer socializing in smaller groups (about six people or less) and planning and carrying out productive activities together. More Delta – ENFP, ESTJ, INFP, ISTJ

Judging Functions: Fi Te Perceiving Functions: Ne, Si

Typical Delta quadra group behavior:

Discussion of interesting facts about people and places. Enjoy group outdoor activities. “Live and let live” attitude. Engage only in “productive” activities and discussions. Prefer smaller groups. Emotionally subdued; generally serious, but with periodic funny moments. More

So, when people start talking about their opposing types being their opposite lettering’s, it’s very incorrect. For me, being an ISFP my opposing type is likely to be ESFJ. An INTJ’s will be an ENTP, and so on.