Controversial hot topics for the next generation.

As far as future controversial issues, I predict that group marriages will be an issue in the next 15-30yrs (if it even takes that long). No doubt all of us will be railing about how marriage in our day was between two adults.

Funny you should say that. I actually see society moving away from the concept of marriage, at all. Not just in the sense of skipping the formal ceremony and simply cohabiting, but often not even that. A society of essentially single people, who may or may not spend a night or a year with someone, or someone(s), but never any formal or officially recognized commitment.

Both that and group marriages, though, aren't nearly as much of a controversial issue as pedophilia. People who are not religious don't generally have any problem with adults living however they want, as long as they don't harm anyone. Personally the only issue I see is with responsibilities and privileges of parents and children. Just how many parents can or should a child have?

Another issue that is controversial, and often mentioned in the same breath as pedophilia, is incest.
But I'd rather not get into that, and must also ask you all to put the pedophilia topic aside, as we are still a child-friendly site.

A different but equally shunned topic is that of mental ethnic differences.
While it is undeniable that there are physical differences between ethnic groups, from the easily observable differences in skin and hair, to genetic diseases such as Tay-Sacks or sickle-cell anemia, it is taboo to suggest there might be such differences in the brain. The famous Asian studiousness, African sense of rhythm, or German punctuality, must be an unwarranted stereotype at best, or a cultural element at worst. Nurture, never ever nature, and don't even try to get funding for a study that might show otherwise, or you'll be branded "racist" and "Nazi". Is this something that should be changed? It's science's job to seek knowledge, but perhaps there are things society is not ready to know?

And in the same vein of ethnic differences, are cultural and religious issues. We are seeing places in Europe disallowing shechita (Kosher slaughter), as cruelty to animals. France is having issues with women wearing traditional Islamic garb in schools. And so on. What should be the bounds of Freedom of Religion?

I agree with Kunagisa, that gene therapy and genetic manipulation in general (as in food plants and animals) is going to be getting bigger and bigger and cause much heated debate in years to come.

And if we're talking science-fiction, and somewhat related to something KhainiWest touched on, artificial intelligence might become an issue as well. Just how "human" can or should computer programs to be? And at what point can we say the machine has developed self-awareness, and should be given certain human rights?