Humans are logical creatures, and as surprising as this might be, when we visit a website our minds make a series of decisions that affect the actions we take. The ability to reason enables us to form judgments, reach conclusions and make decisions. If, on the web, we weren’t able to think on the spot and then take action, we would trap ourselves in crippling situations of mindless clicking.
Behavioral psychology is an advancing field, and we web ninjas need to understand something about psychology in order to make usable websites. If we understand human needs and emotions — how we interpret what we see and how we choose to act — then we will better understand our site users. We’ll be able to choose and create meaningful layouts, typography and colors.
This article is no substitute for a degree in psychology (so don’t give yourself an honorary Ph.D. after reading this). Also, the items mentioned here don’t account for every circumstance, because no two people are the same. Yet by understanding the theories outlined below (there are no hard facts in psychology, just theories), you can better understand how your design work will be perceived and used.