v. 33 (release). I noticed that if I have a significant tech lead over AI's, tech level of emerging civs depends on culture group. If they are from my culture group, they are in the same era like me (or just at the edge). If they are from some other group, they are on pair with the other AI's (so much below me). Two examples (both as Poland, so European culture group).
1. Me at late Renaissance, AI at early Middle Ages. I was sending my spies to rival civs and supported rebel fractions. When Germans emerged, it turned out they were researching Leadership. My decision was to destroy them (a piece of cake for my highly promoted army), so they could not trade extra techs to my rivals...
2. I have cleared my continent from AI, got tech lead, made a footstep into Classical Era (Monarchy, Meditation, Currency) but I was busy with remaining Ancient techs. Civs at another continent (there is one more, but no contact yet) were in early-middle Ancient (researching Metal Casting and so on). One of Barbarian towns at my continent turned into Armenia. It turned out they were researching Monarchy, so they were almost on pair with me.
I plan to download v.34 soon and I will check if anything has changed.
S.