Research on the effects of sport participation on personality has shown that

I believe the answer is: sport participation increases aggression

Sport participation would most likely cuase deindividualization.
This would make each participants to forget their personal identity and immerse themselves in a group cause.
So, when the group that they support is receiving unwanted outcome, this could trigger aggression that would be directed toward another group.

1190 is your answer! the way you get it is 1400 - 15% =1190 : )

Very cool! free points wooo