Is joining the math club social sucide?

Who cares? Part of gaining maturity is doing what suits YOU and is best for you. No one gives a tin fart what a bunch of airheads thinks. Someday when you have a decent career and your social butterflies have a houseful of screaming brats in doody diapers, you can look back and laff.

Not at all. It will get you into a group of people who share the same interests as you and who are very similar personality-wise to you. You might find you share more than just an interest in math -you all might like the same books, movies, and more. Social suicide is pretending to like things you don't like and changing your whole personality in order to make other people happy and to fit into a group with which you have little in common. Be yourself, ultimately it's really the only thing that will make you happy.

Cady Heron managed to be both Spring Fling Queen and a member of the math club, you too can achieve such accomplishments

No. Not all kids are jerks, just some of them. I was in slide rule club in school and I was popular.

It would be social suicide but if you enjoy it then go for it

No, not at all.

You are doing what you think is fun, and as a bonus it helps you in your classes.

The people out there who think that it is a bad idea socially are not the people who would be in math club anyway.