I will preface this post by first stating that I am not a psychologist nor do I understand exactly how the brain works. I am a designer and as a designer I feel it is important to at least understand how people view a design and best practices for a good user experience.
So, what I will do is break this down into a few models or ideas that we at REM keep in mind when coming up with designs.
Building trust with visitors
Probably the most important aspect of any website is ensuring your visitors “trust” you/your company. How else are you going to get them to contact you, buy something off of your site, or generally just consider you when comparing you to your competition?
So, how do you build trust with a design:
Your brand should carry through to all of your marketing initiatives. Logo, colors and imagery type are all important factors that should be consistent. Creative use is important but again, consistency is key.
Placement of items
Similar to the concept of keeping things consistent, there is a reason why items are placed in certain positions on a web page. Typically, people will scan a page using either a clockwise or Z pattern. So, they start at the top left then scan across the top and work their way around and typically end up back at the top left.
This is why logos are usually placed at the top left or center, navigation then important imagery and tag-line below that, and other calls to action or relevant information just below that. This ensures the important items are recognized even on the initial quick scan that takes place by a visitor.
Room to breathe / Buffer
I know, I get it, you want to make sure that everything important is on the homepage of your site and you want visitors to do as little scrolling as possible in order to see it all. This does make sense; however, if you bombard people with too much you will confuse them, disorient their attention, and lose the trust - which is the whole point of all of this.
So, buffer space is very important. It is amazing how adding some whitespace to areas of a design can make a lot of information a lot easier to digest. It is also more pleasing to the eye which will result in a visitor spending as much time as possible on your site.
Obviously, there is a lot more to the psychology of Web Design (color, imagery, emotional triggers, testing with focus groups) but I just wanted to keep it simple and offer some reasoning behind a lot of what we do.