As a shaddchan, I choose no to tell the person the reason if I feel it will only come to hurt them.
Should one inform the other party they have been dumped because they:
-Are not intelligent?
-Are not attractive?
IMO – absolutely NOT. BIG NO-NO. Beauty, as we always say, is in the eye of the beholder, so to tell someone the date thought that he or she is not attractive is a) hurtful, and serves no purpose and b) may not even be true in any sense of the word. The person may be very attractive (everyone is attractive to SOMEone), and attractiveness is a very subjective thing. Personally, I think that a boy or girl who would even GIVE that as an excuse, is really immature and mean-spirited. My girls have gone out with a number of guys who would be considered to be ordinary-looking, certainly not conventionally good-looking, and they were not attracted to them for whatever reason. They even went out more than once, because they thought the person was a nice guy and deserved the courtesy of giving it a chance. But they were not attracted. They told the shadchan they thought the respective guys were very fine, nice guys, but there was just no chemistry even after the second date. Only in one case did one of my daughters give a more detailed reason, because the guy had acted like a rude jerk, first by showing up 3/4 of an hour late, with no apology or even an excuse (they had previously confirmed the time)talking on the cellphone constantly, badmouthing and deriding other dates he had gone on, etc. My daughter felt the shadhcan deserved to know that his midddos could use some improvement, and if she was going to continue to set him up with other girls, she should be aware of this. The intelligence issue is another thorny one. I would not do it, it would just hurt that person to be made to feel he or she is stupid. I would rather say, He or she felt you did not really have much in common, and they are lookking for someone who shares their interests. That is a more innocuous statement, it does not reflect on the person’s brains, looks, personality or character. You really cannot fault a girl who loathes sports, for not wanting to date a sports jock, who refuses to miss a game.
It is not enough to make a shidduch – one needs to educate the person being set up,in the value of menschlechkeit when talking to the shadchan. If a person appears to be an insensitive clod one too many times, he or she will end up not being set up by anyone.