Off the top off my head, and not being all together technical about it..
Seven's want, want, and want. They have desire's and they want them. Seven's are high energy, and have big appetites.
Also known as the enthusiast..
They are part of the 'thinking' or 'head' triad, (9 enneagram personality types can be divided into three 'triads' each pertaining to their own 'function' and core emotion). Although it has been argued by some that it's been misplaced and actually belongs to the 'body' triad.
I think it's fine in the 'head' triad tho. 7's are associated with hyper activity. And most likely of the mental kind.
This is a quick and poorly written reply, and I'm not meaning to offend you in anyway.
I'm part 7.
And I could be wrong anyway..