tech tree query

[alancsilver]

I was looking about what I wanted to research next. I was eyeing Nationalism and Education. I saw something that I can't explain, but I am hoping someone can clarify for me.....

Both Nationalism and Education take 4657 and I have 0 right now for each tech.

The technology advisor is telling me t will take 12 turns to research nationalism and 14 turns to research education. Why the discrepancy?

Screenshots (hopefully) attached.....

Thanks everyone...

 

[Sengir]

You've got both prereq for nationalism, earning yourself a discount (not sure about the amount).

 

[ahmedhadzi]

If technology is known to other civilizations, you also get discuount to it, there is a formula somewhere on the website but I'm to lazy to look for it now