[MGoelz]

Well, have you tried talking to this person? You said it seemed he/she doesn't recognize that he/she is doing this. Maybe they aren't intentionally picking on you? Do they do this to other people?

One of the issues may be that you are one of the only ones speaking up, and this person feels they have to bring up the opposing viewpoint every time. You also said that the team doesn't want what this person thinks all of the time. If that is the case, other members of your team need to speak up and make it clear what the majority of the team thinks. If it is really out of hand, and you speaking to him/her doesn't seem to have an impact, maybe see if a teacher or mentor will talk to this person.

Remember, it isn't bad to bring up the opposite idea; it is only wrong when they are intentionally bashing your opinions and ideas. Perhaps everyone could use a reminder in the field of rumors as well. Spreading rumors isn't going to build up a team, it is going to break it down. Maybe gently saying this to that person will help. I don't think any person would want to destroy a team's dynamics.

If all else fails, stay strong and keep voicing your opinion. Back it up with facts, give details, and be confident. Remind this person you are a team; there is no need to verbally attack somebody else's opinions, especially since no opinion is technically wrong. Everyone is entitled to their opinions and everyone is entitled to rights of voicing those opinions...nobody should be hindering that.

Perhaps even trying to have a meeting where everyone writes down their ideas/opinions, rather than voicing them, and then have a mentor or other figure read them. Don't allow anyone to speak. Maybe this way, this person will see that there are lots of opinions and if he/she wouldn't attack them, more people would speak up and broader range of ideas would be presented, which would mean more options, ultimately benefiting the team. It would probably help everyone understand each other better and bring your team closer together.