One of the most interesting topics for me in PSYCH 1001 was social psychology. I found it fascinating how people act differently in groups and how drastically their actions differ from their personality. I now recognize a lot of the signs of groupthink, group polarization, social loafing, etc, in my past and present. I know I've been subjected to it. Everyone has.
The thing that strikes me most, though, is the Bystander Effect. If someone is hurt or in need of help in a crowd, no one will do anything because they'll think someone else called for help or assisted the person in need. No one will do anything to help.
But there's a simple fix to this: simply be aware of it. If one is aware of the Bystander Effect/diffusion of responsibility, then they can take measures to counteract it and help those in need instead of assuming someone else did. It's just another example of how knowledge can influence how someone's attitude towards a situation changes. Knowledge brings power, after all.
I liked learning about group think. I found this topic very interesting and find myself looking for it when I am working in small groups.