Within a group, you will have members with different learning styles. Based on how they use their senses, teachers could have a combination of:
visual learners – need to see
auditory learners – need to hear
tactile / kinesthetic learners – need to touch or do something
Further, some students will think more concretely while others are abstract in their thinking. Some students will need instruction to be sequential while others can randomly go with different thoughts in different directions from different perspectives.
Teachers themselves will have a learning style that could push them to teach primarily one way rather than take a multidimensional approach. As a result they could have some students who are bored or frustrated. Just one or two students in that state could greatly affect group dynamics.