Year one in university psychology courses new undergraduates are taught about the importance of the primacy and recency effect (or Serial Position Effect) in memory recall tasks.
For over a century studies have shown that when a subject memorises a list of items, the primacy effect means they are more likely to recall the first items in a list, and the recency effect means they are more likely to recall the last items in the list.
Why am I bothering with this? Well there’s a primacy and recency effect that is well know in menu design and information architecture. Users under pressure to make decisions to act or not to act, buy or not to buy, will pay more attention to items at the begining and end of your menus. These are the premium spots, so don’t waste them on content that doesn’t drive the primary goal of your site.