My college students are at a stage in life where they are seeking self-knowledge. I use the Myers-Briggs personality index (which is derived from Jung's personality types) in conjunction with studying communication strategies.

We all tend to infer that everyone else is just like us and will respond to communication just like we do; it's human nature. Group activities and group discussion reveal ways that other personality types may respond differently to exactly the same activity/messages.

We all say somewhat glibly, "Everyone is different; people are just like snowflakes" blah, blah.

But unless we have some insights into the ways that other people can be different, it doesn't help us much to figure out various people and situations. I expect that it is more helpful for my students, whose experiences of other people may be limited, that someone who has already acquired greater breadth of experiences.

I don't think the personality index in an end-all and be-all; there are so many variations and complex interactions between the four dimensions of personality that comprise the 16 types that it does ultimately result in "snowflakes" of infinite variety. Still, it can help us group people into broad categories that offer insight into ourselves and others.