What's a Quadra?
This is a discription from the Socionics web site.

" A Quadra is a group of 4 people sharing relations of Duality, Mirror and Activity within the group. The Quadra is a structural unit of the Socion. It gives one the feeling of psychotherapeutic and physical comfort, full understanding and emotional satisfaction. Misunderstandings hardly ever occur, there is no fear of making mistakes or of appearing unconfident. Initiative shown by one within the Quadra quickly finds response and support from other Quadra members. Together they quickly find a way to collaborate or to find practical solutions. The Quadra gives a feeling of cosiness, comfort, security, confidence and understanding. Relations of Activity within the Quadra mobilise the strengths of its members to act in one direction. The Quadra is the second energetic whole after Duality. "

 What are clubs?
This is a discription from the Socionics web site.

" A Club is a group of 4 people that share Mirror, Contrary and Quasi-Identical relations within the group. The Club can also be called the "Brain Storm" group. This group is organised by the intellectual abilities of its participants and concentrates mostly on theoretical discussions about aims and tasks or interesting exchanges of opinions. Problems are normally discussed from every side. Mirror partners help each other to see the other half of the outer world, Quasi-Identical partners help each other to see the other half of the inner world and Contrary partners help each other to see the opposite side what one partner usually cannot see. There could be very intense intellectual activity within the group, however it does not produce a feeling of tiredness in the participants. This activity can periodically decrease and then increase again when a new task appears. The Club can provide quick and effective solutions for different problems, but it does not form one energetic whole such as the Quadra and the practical implementation of produced solutions is not effective or can be difficult."

 The term's midriffs and mooks I got from the TV show Frontline. The show was about the young male and female groups that advertisers try to appeal to. They try to figure out what these groups think is cool. The midriff group seems to be centered on SF values. I do not know if Brittany Spears is a SF but her message has a broad appeal to SF's. And I think its no accident advertisers try to appeal to this most common female group. They certainly don't try to appeal to the female NT club. Spending millions on promotions to appeal to a group of female hackers? I don't think so.
 The name and stereotypes labeling are more genres to give you some idea what these groups are about.

Now everyone get to be the boss and bossed too.

 The Inspection loop includes four personalities where each person is Inspector and Inspectee at the same time, so the energy gets distributed around the loop. This takes the tension off otherwise unfavorable relationship and conflicts are less likely.

Now everone can be and have a guru.

 The idea of Instruction loop is similar to that of Inspection loop. Four people, and each one is a Transmitter to somebody and a Receiver to somebody else. Instruction loop is a very productive and creative group and can accomplish a lot. Especially progressive can be a group of 8 people from two "parallel" instruction loops.

Healthy Groups

 It's been noticed that a person's health can be affected by the presence of other people. Sometimes the influence is positive and sometimes is negative. Experiments have shown that groups of certain personalities have therapeutic action on people inside the group - high blood pressure subsides, and people generally calm down. There are 8 healthy groups:

Bouquets

 Groups of unhealthy influence are called bouquets. When a bouquet forms among ill people, the health of people inside the group worsens or the recovery slows down substantially. The effect of the bouquet on healthy people is also negative. People get tired sooner and tend to be more nervous than usually. There are 4 bouquets:

 Another behavioral method that can aid finding a person's type is by noticing how a person uses feeling.
Noticing whether they introvert or extravert feeling.
I have adjusted this method to the way Soconics lays out the different functions.
This method is elaborated on in the book called The Art of Speed-Reading People.
The title is self explanatory to what this book is about.