Socially encouraging  

A group setting presents an opportunity for the participants to express their thoughts and ask questions as they work with other people. 

Learning a new concept with a brief individual exercise provides just enough stimulation to keep it interesting! Then a group activity encourages the participants to learn from each other. 
 

Stimulating and relevant topics  

A wide variety of subject matters are important to the modern world. When people have a great selection to choose from, they are excited to learn more--not only about themselves but also the people around them. This will make them better able to strengthen their other relationships. 

Intimate groups

The limited number of people per group makes it easy to learn and still have social interaction. When people are able to see their peers, they get to know them personally. This encourages people to express themselves in ways that they might not otherwise be able to. 

20 minutes 

The brief time frame is just enough to be challenging but not overwhelming.  Too much information can distract someone who wants to just deal with "one thing at a time".