Personality type testing.
Well, basically, afaik humanity struggles to find friends, form better connections.
Because usually when I met some one nice who like some thing that I do, after awhile I see it's hard to cope with mismatch on other tastes.
So few tests like MBTI, Big5, (even Zodiac Horoscope matching) were invented.
But those said, don't do perfect matches.
Are you aware of any really good psychological tests to match strangers to make them friends?