Biologist
Emperor
You don't receive affinity levels for researching techs. You receive affinity points and it's possible that you already had some whereas the AI hadn't even though you both appear to be level 0 Harmony. You might already have accrued some from a quest decision.
And, yes, when you steal, you get a random tech from them that you have not researched yourself.
I realize that researching techs doesn't directly grant affinity levels, I simply meant that the net effect was that I gained two levels of Harmony from all the exp I got. That said, my point about the AI having no apparent experience in Harmony is moot, since the civ in question has nothing to do with which tech one receives.
As others have stated, I understand why this was done from a balance standpoint, but it's unsatisfying from a roleplaying/immersion standpoint. Maybe what they should do instead is remove the tech stealing option and leave "steal science" as the sole research-focused espionage mission. Then they could implement a system where capturing an enemy city or outpost has a percent chance to grant an enemy technology for free, with cities having a higher chance than outposts.