Originally Posted by
misutii
Suomea most of the pairings you discuss are quasi-identicals, it was the first relation that Aushra identified when she was coming up with socionics. Quasi-identicals look confusingly similar on the surface so they're often mislabelled at first...
I think you pretty much hit at why already, I see it as being due to both quasi-identicals, i.e. INFp/INFj having the same strong functions and the same weak functions, in this case Fe/Fi/Ne/Ni are all strong, Se/Si/Te/Ti are all weak.
However once you get to know these people better, and they become familiar with you, then they become less inhibited and act more naturally, this is when you recognize that the similarities were much like an optical illusion because INFps value Ni/Fe/Se/Ti compared to INFjs valuing Fi/Ne/Si/Te. Giving them what they value leads to friendship, marriage, babies, grandkids, a sweet happy sugary death. Giving them what they don't leads to either loss of interest, or sado-masochistic pleasure, marriage, one baby and 2 miscarriages, alcoholism, and a miserable painful bitter, as black coffee and grapefruit juice with a touch of cheap whiskey, death lol