Does OS X scale the resolution of my screen? I'm using an Early 2015 13" MacBook Pro with Retina Display and it has a native screen resolution of 2560 by1600 pixels, the default setting says "looks like 1280x800", and it seems like every program thinks this is my resolution I've set it to the "More space" option, which says "looks like 1650x1050", for now.

This is still a problem for me, everything looks far too big for what I need. Is there any way to make the 2560x1600 display to look like "real 2560x1600"? Or is this just a thing OS X does?

PS: I've tried this in OS X El Capitan and macOS Sierra.
You can use an app like Display Menu, available for free in the App Store, to set the Display to its highest resolution, as well as other available resolutions.

Note that there is a paid Pro version too, for $1.99 USD, which offers AppleScript Support, Retina Resolutions which displays all resolutions with a mouse click and Bookmarks for Quick Access.

I've used the regular version for over 3 years now on my 15" Mid 2013 MacBook Pro with Retina Display and it's done all I've needed without upgrading to the Pro version. That said, you might find the additional Pro features worth the $1.99 USD.