It took some searching but I finally found where to fix the “resolution problem” in Photoshop. Select the Photoshop application in the Finder and choose File > Get Info. If you have a Retina display, under General, there will be an option to “Open in Low Resolution” check that and restart Photoshop. When you reopen your image it will appear like you are use to.
The image on the left was opened in Photoshop on the retina display as normal. The image on the right is opened with “Open in Low Resolution” checked.