I am going to install 3/4" thick by 5" wide solid hardwood in my house. I was told that you have to use glue as well as nailing. This does not sound right to me. Anyone have any insight to this?

I don't think you "have" to glue this floor, I dont even think it is a good idea.
However, I might suggest using T & G glue in the end joints to prevent potential squeaking down the road.

Wide plank solid flooring is more susceptible to cupping, so NWFA recommendations for 5" and wider flooring is to either screw and plug at end joints, or apply an approved wood flooring adhesive. Doing this won't eliminate the possibility of cupping completely, but will reduce the likelihood and degree to which it cups. Check with the manufacturer for what adhesive they recommend so you don't run into any warranty issue.

By gluing as well as nailing, you inhibit the flooring's ability to expand and contract as easily. This is a good thing, as long as you keep the interior environment within the normal living conditions. 20 yrs ago, we never glued down plank. But Carlisle started recommending it on their products and it worked so well, it has become an industry accepted practice. I do it by running vertical beads of a urethane adhesive every 6 to 8" apart. It is neater this way and maybe less expensive than troweling out an adhesive.